AeroElectric-Archive.digest.vol-id

September 12, 2008 - September 28, 2008



      Thanks, Vern
      
      -----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Speedy11(at)aol.com Sent: September 12, 2008 9:42 AM
Subject: Re: Switch problem ***MAJOR UPDATE***
Vern, Very interesting problem and investigation. Thanks for sharing it with us. I noticed that the fast-on is stamped 18-22 gauge and your wiring diagram lists 14 gauge wire. Could that difference have caused a weak crimp? Stan Sutterfield What is causing these recurrent problems? One theory is bad crimps, the other is bad switches. Maybe one is causing the other. If a crimp is faulty, and causes heating of the terminal, perhaps this triggers problems in the switches, which then heat up as well. Or maybe it's the other way around. _____ Psssst...Have you heard the news? There's a new fashion blog, plus the latest fall trends and hair <http://www.stylelist.com/trends?ncid=aolsty00050000000014> styles at StyleList.com. ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Switch problem ***MAJOR UPDATE***
Date: Sep 12, 2008
Bob: A couple of switches, the burnt fast-ons, and some sample terminations on your way by airmail today. Hope you have time to add a learned second opinion after you have a look. Thanks, Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Robert L. Nuckolls, III > Sent: September 11, 2008 2:16 PM > To: aeroelectric-list(at)matronics.com > Subject: RE: AeroElectric-List: Switch problem ***MAJOR UPDATE*** > > > > --> > > > The photo at: > > http://www.vx-aviation.com/rv-9a/photos/Electrical/IMG_0935_2.JPG > > shows very localized discoloration of the terminal > insulator. There's a large temperature gradient when > you consider heat flow path from a high-resistance > contact within the switch out through riveted joint, > terminal tab, fast-on socket and to the plastic insulator. > > I'm not seeing any signs of heating of the switch-tab > or the fast-on socket. The fact you ARE seeing so much > effects of heating due to poor contact in so many places > places the application tool in question. See the wire- > grip photos at: > > http://www.aeroelectric.com/articles/CrimpTools/crimptools.html > > This is a critical issue for mating tools-to-terminals-to-wire. > > If you would care to send me some exemplar terminals installed > on wires, I'd be pleased to get a look at the microscopic details > of the wire grip. > > Bob . . . > > > > > > ________________________________________________________________________________
Date: Sep 12, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Switch problem ***MAJOR UPDATE***
> >Why has the problem only happened with toggles as opposed to rockers? Don't know that it's been this selective. Just because you're not aware of someone's difficulties/observations doesn't mean they've not happened. >Obviously the switch is the problem. Has ANYONE called Carling Switch and >bitched?? Why not? What do they say? Despite what Bob says, 115 VAC >switches should never be used for LV DC high-current applications. Do what >the manufacturer suggests. That's what's printed on the side of the switch >Bubela. Otherwise you're on your own. Really? It appears that you've not studied the physics of making connections between wires and terminals nor is it apparent that you've studied and understood the physics of relay and switch contacts. It is also glaringly obvious that you have not read the article at: http://www.aeroelectric.com/articles/Switch_Ratings.pdf nor studied the ratings charts for switches excerpted from Honeywell data similar to that found here: http://aeroelectric.com/Mfgr_Data/Switches/Microswitch_TL-Series.pdf Okay Eric, call Carling. Exactly what would you say? What makes you think you'll be placed in contact with someone that actually understands what's happening? What would you expect them to say in response? If you light into Carling with the same display of ignorance as you've blessed us with here, it is unlikely their response would be helpful to you or anyone else. >Bob--"Gas-Tight" Can you even SHOW me a "Gas-Tight" Faston connection? >This silly regression to concern about gas-tight Fastons is wildly >delusional. In my previous life we used Fastons for decades at 25 Amps DC >with short excursions to 300 Amps with nary a failure. A hundred >different people did the installation. The choice of tools by the >manufacturing department never became so ANAL. Eric, 'gas tight' has nothing to do with fast-ons in particular. We're not talking about interface between the fast-on and the switch tab. We're talking about the interface between strands of wire and the terminal as determined by the design of the crimp tool. If you had bothered to read and understand the article I cited at: http://aeroelectric.com/articles/CrimpTools/crimptools.html then this would have been clear to you. Understand this my friend, gas-tight is not my term but that of my teachers who have accurately and patiently shared their their knowledge and understanding in volumes of printed data which is just as accessible to you as it is to me. Further there are gas-tight components of the interface between a fast-on female and the mating tab. If you had bothered to attend the seminar I offered at Plymouth a few years ago (I would have let you sit in for free) this would all have been explained to you. >I supply 50A Fastons with my high-current SSRs and I don't lose a wink of >sleep. The terminals don't get as warm as a kitten's belly. I'm pleased that you're sleeping well. I often lay awake for hours . . . my head may be busy figuring out ways to disassemble the simple-ideas of a failure into a root cause . . . or assembling the same simple- ideas into a new and useful product. >"Everything you've learned in school as 'obvious' becomes less and less >obvious as you begin to study the universe. For example, there are no >solids in the universe. There's not even a suggestion of a solid. There >are no absolute continuums. There are no surfaces. There are no straight >lines." Your selection of authors for words of guiding wisdom have always been a mystery to me. Never have you seemed to embrace the notion of simple ideas (obvious profundities) and their artful assemblage into useful inventions. Instead, your choices seem to frame your writing with pessimistic uncertainty if not despair. Buckminster Fuller would be disappointed to see you quoting him in this manner. His genius and wisdom are beacons of enlightenment and discovery for millions. Yet you seem to use this passage by Fuller as some rationale for attacking what we do here with little demonstrable understanding or willingness of your own to teach. Had you contacted me directly with this fusillade of wild pitches, I would have been inclined to be more discrete in our exchange. However, you've elected to show us the best you have to offer in open forum carried forth with aspersions on my knowledge, skills and integrity. Well, it was YOU who picked the time, place and weapons sir. I will defend myself and the work that honorable and serious students of our science and art are doing here. Bob . . . "There cannot be a greater mistake than that of looking superciliously upon practical applications of science. The life and soul of science IS its practical application." -Lord Kelvin Now THAT's what I'm talking about! ________________________________________________________________________________
Date: Sep 13, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Toggle Switches with Fast-On Tabs
Let's lay out all the simple ideas behind the design fabrication and operation of a toggle switch fitted with fast-on tabs for the purpose of discovering a failure mode and deducing a remedy. I'll refer the serious students to the quick-n-dirty sketch at: http://aeroelectric.com/Pictures/Switches/Toggle_Switch_with_Fast-On_Tabs.jpg This cross-section will allow us to trace the path of current flow through the switch as follows: Electrons come in via Wire(B) and pass to the fast-on terminal through wire grip(1) and then on to the fast-on tab(C) through a high-pressure metal-to-metal terminal/tab interface(2). Current must then pass through a high-pressure, metal-to-metal joint(3) to the contact(D). A low-pressure, metal-to-metal contact/contact interface(4) carries current to the teeter-totter(F) via another high-pressure, metal-to-metal joint(5). Current flows through the teeter-totter to a low-pressure, metal-to-metal sliding joint(6) at the top of the saddle(G) and then down to a high-pressure, metal-to-metal joint at the saddle to rivet interface(7), through the plastic housing(A) to another high-pressure, metal-to-metal staked joint(8) and thence on to the fast-on-tab. From the fast-on-tab, we find another high-pressure, metal-to-metal joint at the terminal/tab interface(9) and finally, another high-pressure, metal-to-metal joint at the terminal's wire grip(10). So if you count them up, there are TEN, conductor- to-conductor joints that carry current through this switch installation when the switch is closed. By inspection we can deduce that the weakest links in this conductor chain are at the low-pressure, metal-to-metal, NON GAS TIGHT joints at (4) and (6). Indeed, the first switch failure we considered gave us physical evidence of a failure at (6) that produced a slowly progressing failure of the switch. This study was described in detail at: http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/Anatomy_of_a_Switch_Failure.html Now we are pondering a demonstrated case of repeated failures over a period of years in one aircraft. Here are some of the hard data points: (a) All of the switches involved are Carlingswitch toggles with fast-on tabs. These switches are an exceedingly mature design that dates back at least 50 years. IF the root cause of failure lies with the switches, then it's most likely a failure of process and not of design. (b) All switches showed signs of heating on terminals that are also on "loose rivets" at (3) or (8). The fast-on terminals also showed signs of over-heating in the form of discolored insulators over the wire-grips. (c) While the majority of switch failures were used in circuits that carry substantial amounts of current (strobe and landing lights) the first failure reported was in a master switch that carries 1A of contactor current and field current of perhaps 4A max with an in-flight average current on the order of 1A. (d) A photo offered at: http://aeroelectric.com/Pictures/Switches/VL_Switch_Failure_2.jpg shows distinct signs of over-heating at the terminal's insulator but no overt signs of overheating in the metal parts under the terminal. I posited the hypothesis a few days ago that IF the source of heating came from within the switch and IF temperatures rose high enough to discolor the terminal's insulation, then temperatures on the metal parts under the terminal would be high enough to discolor their surfaces as well. For example, in the photo at: http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/b.jpg We see an overheated and loose rivet. We also see signs of discoloration due to accelerated corrosion of the fast-on tab adjacent to the rivet head. These were the overt signs visible from OUTSIDE a switch that was in serious trouble from heating effects INSIDE . . . the fast-on-terminal was not hot enough to distort the shape or color of the terminal's wire grip. Now, the loose rivet phenomenon is easily explained by a degradation of structural integrity of the switch's plastic housing(A). Further, since the failed switches have obviously been running hot, it follows that the plastic has lost structural integrity due to heating . . . what is NOT obvious is whether the initial heat-source came from INSIDE or OUTSIDE the switch. (e) We know that hundreds of thousands of switches using this design and process are flying on aircraft. IF there is a problem with the switches, then the BIG puzzle to be solved is why we find a suite of failures spanning years of switch production batches and many flight hours of the subject aircraft. The astute investigator is obligated to consider all features of the current path study cited above and either confirm or discard each of the TEN metal-to-metal connections as candidates for root cause of the failures. Okay, this dissertation illustrates our of understanding at the time of this writing. It's not only useful but necessary to discount or confirm the integrity of wire grip joints on the terminals ESPECIALLY in light of localized heating observed on the wire-grips of the terminals. This line of investigation is further encouraged by analysis of the probability of such concentration of switch failures having root cause in design or construction of the switches. This consideration alone is strong suggestion of an ALTERNATIVE EFFECT COMMON TO ALL THE FAILURES. On a related topic it has been suggested in the pages of this forum that Fast-On terminals have no "Gas Tight" qualities. For clarity let us agree on the meaning of gas tight. In the dissertation above I've used the terms high-pressure and metal-to-metal to describe the interface between two conductors. By high pressure, I'm speaking of conditions severe enough to deform metal, i.e. upset its surface or shape. Keep in mind that this kind of activity implies pressures in the tens of thousands of pounds per square inch. In the context of gripping the strands of wire in the crimp of a terminal, the term "gas tight" is very descriptive of the design goal. Consider the sketched cross-section of a fast-on joint which I've posted at: http://aeroelectric.com/Pictures/Terminals/Fast-On_Physics.jpg We speak to this drawing during the weekend seminars and point out that most individuals look at a Fast-On terminal and incorrectly deduce that the spring forces at the ends of the grips(A) provide an enduring connection to the tab(B) at the flat interface between terminal and tab at (2). Consider that when you push the Fast-On terminal onto a tab and pull it off, an examination of the area under the tips of the grips at (1) will show bright lines or scratches in the tab metal surface. Tiny? yes. Pressure? Pushing the terminal onto the tab plows furrows in the surface of the tab i.e. exerts pressures in the tens of thousands of PSI. The pressures on the back side of the interface at (2) are a tiny fraction of those found on the front side. Therefore, I suggest that not only are the interfaces at (1) gas-tight (due to the intimate contact of terminal and tab) the interface at (2) is not gas tight. While (2) may contribute significantly to joint conductivity when shiny and new, it's contribution ten years hence is a small fraction of the total. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Switch problem ***MAJOR UPDATE***
> > >Bob: A couple of switches, the burnt fast-ons, and some sample terminations >on your way by airmail today. Hope you have time to add a learned second >opinion after you have a look. Great. I've published a working document that lists all the simple-ideas to be considered in this study of your switch problems. Taking a good look at joint integrity of the wire-grips is a good place to start. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2008
From: Scott Klemptner <bmwr606(at)yahoo.com>
Subject: Re: AeroElectric-List Digest: 11 Msgs - 09/12/08
Vern, you quoted Carling switch ratings, but if you read further down on the page, you find the following: "Types of Loads: An electric load is the amount of electric power delivered or required at any specific point or points on a system. The requirement originates at the energy consuming equipment of the consumers. More simply put, a load is the piece of equipment you turn on and off. Resistive loads primarily offer resistance to the flow of current. Examples of resistive loads include electric heaters, ranges, ovens, toasters, and irons. If the device is supposed to get hot and doesn't move, it's most likely a resistive load. Inductive loads are usually devices that move and normally include electric magnets, like an electric motor. Examples of inductive loads include such things as power drills, electric mixers, fans, sewing machines, and vacuum cleaners. Transformers also produce inductive loads. High Inrush loads draw a higher amount of current or amperage when first turned on, compared to the amount of current required to continue running. An example of a high inrush load is a light bulb, which may draw 20 or more times its normal operating current when first turned on. This is often referred to as lamp load. Other examples of loads that have high inrush are switching power supplies (capacitive load) and motors (inductive load). . . . . . L & T Ratings An "L" rating denotes the ability of a switch to handle the initial high inrush characteristics of a Tungsten Filament Lamp on AC voltage only. A "T" rating is the equivalent lamp load for DC. H Rating An "H" rating denotes a non-inductive resistive rating. Ratings listed in Carling Technologies' product information may appear with the symbol "H" or with the words "non-inductive" or "resistive". "H" ratings are typically required for switches used in commercial oven applications." Are you sure you are using the switches within their rated specs??????????? My experience using AC rated switches on DC circuits with high inrush currents (landing/taxi lights and strobes in particular) is failure after failure. Eric....this includes ROCKER SWITCHES TOO!.... Cessna rocker switches used in the 70's for example (AC rated "Mr Coffee Maker switches). My $.02 worth...... Scott A Klemptner bmwr606 on Yahoo IM What if the Hokey-Pokey IS what it's all about? ----- Original Message ---- From: AeroElectric-List Digest Server <aeroelectric-list(at)matronics.com> Sent: Saturday, September 13, 2008 1:55:46 AM ________________________________ Message 7 _____________________________________ From: "Vernon Little" <rv-9a-online(at)telus.net> Subject: RE: AeroElectric-List: Re: Switch problem ***MAJOR UPDATE*** ... > Despite what Bob says, 115 VAC switches should never be used > for LV DC high-current applications. Do what the manufacturer > suggests. That's what's printed on the side of the switch > Bubela. Otherwise you're on your own. > ... > -------- > Eric M. Jones > www.PerihelionDesign.com ... Hi again Eric. Just to comment on what you said: "DC Rule of Thumb For those switches that list an AC voltage rating only, the "DC Rule of Thumb" can be applied for determining the switch's maximum DC current rating. This "rule" states the highest amperage on the switch should perform satisfactorily up to 30 volts DC. For example, a switch which is rated at 10A 250VAC; 15A 125VAC; 3/4HP 125-250VAC, will be likely to perform satisfactorily at 15 amps up to 30 volts DC (VDC)" http://www.carlingtech.com/products/switches/learn_more.asp?page=switches_amp-rating Therefore, all of my Carling switches are being used according to the manufacturers recommendations. The only gotcha is that the switches are not rated for operating below 0 degrees C. This is probably because the switches are not sealed from condensing moisture. This is not a problem where I live. Vern ________________________________________________________________________________
Date: Sep 13, 2008
From: "Richard E. Tasker" <retasker(at)optonline.net>
Subject: Re: AeroElectric-List Digest: 11 Msgs - 09/12/08
A comment on the below comments: If you look at the schematic Vern posted, you would see that he is using NTC surge limiters on each light. These minimize startup surges caused by the very low cold filament resistance of the lamps. On the other hand, it depends on the time constants of the NTC surge limiters vs the time constants of the lamp filaments as to whether these are effective when in wig-wag mode. Dick Tasker Scott Klemptner wrote: > Vern, > > you quoted Carling switch ratings, but if you read further down on the > page, you find the following: > > "Types of Loads: > An *electric load* is the amount of electric power delivered or > required at any specific point or points on a system. The requirement > originates at the energy consuming equipment of the consumers. More > simply put, a load is the piece of equipment you turn on and off. > > *Resistive loads* primarily offer resistance to the flow of current. > Examples of resistive loads include electric heaters, ranges, ovens, > toasters, and irons. If the device is supposed to get hot and doesn't > move, it's most likely a resistive load. > > *Inductive loads* are usually devices that move and normally include > electric magnets, like an electric motor. Examples of inductive loads > include such things as power drills, electric mixers, fans, sewing > machines, and vacuum cleaners. Transformers also produce inductive loads. > > *High Inrush loads* draw a higher amount of current or amperage when > first turned on, compared to the amount of current required to > continue running. An example of a high inrush load is a light bulb, > which may draw 20 or more times its normal operating current when > first turned on. This is often referred to as lamp load. Other > examples of loads that have high inrush are switching power supplies > (capacitive load) and motors (inductive load). > > . > > . > > . > > . > > . > > L & T Ratings > > An "L" rating denotes the ability of a switch to handle the initial > high inrush characteristics of a Tungsten Filament Lamp on AC voltage > only. A "T" rating is the equivalent lamp load for DC. > > > H Rating > > An "H" rating denotes a non-inductive resistive rating. Ratings listed > in Carling Technologies' product information may appear with the > symbol "H" or with the words "non-inductive" or "resistive". "H" > ratings are typically required for switches used in commercial oven > applications." > > > Are you sure you are using the switches within their rated > specs??????????? > > My experience using AC rated switches on DC circuits with high inrush > currents (landing/taxi lights and strobes in particular) is failure > after failure. > > Eric....this includes ROCKER SWITCHES TOO!.... Cessna rocker switches > used in the 70's for example (AC rated "Mr Coffee Maker switches). > > My $.02 worth...... > > Scott A Klemptner > bmwr606 on Yahoo IM > > What if the Hokey-Pokey IS what it's all about? > > ----- Original Message ---- > From: AeroElectric-List Digest Server <aeroelectric-list(at)matronics.com> > To: AeroElectric-List Digest List > Sent: Saturday, September 13, 2008 1:55:46 AM > > > ________________________________ Message 7 > _____________________________________ > > > From: "Vernon Little" <rv-9a-online(at)telus.net > > > Subject: RE: AeroElectric-List: Re: Switch problem ***MAJOR UPDATE*** > > > ... > > Despite what Bob says, 115 VAC switches should never be used > > for LV DC high-current applications. Do what the manufacturer > > suggests. That's what's printed on the side of the switch > > Bubela. Otherwise you're on your own. > > > ... > > -------- > > Eric M. Jones > > www.PerihelionDesign.com > ... > > Hi again Eric. Just to comment on what you said: > > "DC Rule of Thumb > For those switches that list an AC voltage rating only, the "DC Rule of > Thumb" can be applied for determining the switch's maximum DC current > rating. This "rule" states the highest amperage on the switch should > perform > satisfactorily up to 30 volts DC. For example, a switch which is rated at > 10A 250VAC; 15A 125VAC; 3/4HP 125-250VAC, will be likely to perform > satisfactorily at 15 amps up to 30 volts DC (VDC)" > http://www.carlingtech.com/products/switches/learn_more.asp?page=switches_am > <http://www.carlingtech.com/products/switches/learn_more.asp?page=switches_amp-rating%20>p-rating > <http://www.carlingtech.com/products/switches/learn_more.asp?page=switches_amp-rating%20> > Therefore, all of my Carling switches are being used according to the > manufacturers recommendations. The only gotcha is that the switches > are not > rated for operating below 0 degrees C. This is probably because the > switches are not sealed from condensing moisture. This is not a problem > where I live. > > Vern > > > * > > > * -- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. -- ________________________________________________________________________________
Date: Sep 13, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: AeroElectric-List Digest: 11 Msgs - 09/12/08
>Vern, > >you quoted Carling switch ratings, but if you read further down on the >page, you find the following: > >"Types of Loads: > An electric load is the amount of electric power delivered or required > at any specific point or points on a system. The requirement originates > at the energy consuming equipment of the consumers. More simply put, a > load is the piece of equipment you turn on and off. >Are you sure you are using the switches within their rated specs??????????? > >My experience using AC rated switches on DC circuits with high inrush >currents (landing/taxi lights and strobes in particular) is failure after >failure. > >Eric....this includes ROCKER SWITCHES TOO!.... Cessna rocker switches used >in the 70's for example (AC rated "Mr Coffee Maker switches). > >My $.02 worth...... > >Scott A Klemptner >bmwr606 on Yahoo IM Scott, Keep in mind that RATINGS have to do with SWITCH SERVICE LIFE generally given in the tens of thousands of cycles with various conditions. Our use of switches in light aircraft is exceedingly light-duty in terms of service life. For example, a master switch (one of those cited in the constellation of failures) operates ONCE PER FLIGHT-CYCLE and carries very small currents compared to the switch's RATINGS. Scott, please review the arguments offered in the piece at: http://www.aeroelectric.com/articles/Switch_Ratings.pdf and explain where you find discrepancies of fact or logic. I'll suggest that had Vern sat in his airplane one afternoon and put 1000 cycles on any of the failed switches, he would NOT have experienced a failure. Yet, over a period of many flight hours and a mere handful of operations he experienced failures that speak to long term effects of ENVIRONMENT that include DEFICIENCIES of process either in fabrication of the switch as described here . . . http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/Anatomy_of_a_Switch_Failure.html or installation of the switch as hypothesized in my earlier treatise published this morning. The old AC vs. DC as a critical driving force in switch life is a myth. Further, it is clear that the study before us has nothing to do with switch life in terms of ratings, operating cycles, or application. Root cause of these failures will be loss of conduction integrity in one or more of the ten metal-to-metal joints that make up the switch's current path. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: AeroElectric-List Digest: 11 Msgs - 09/12/08
> > >A comment on the below comments: > >If you look at the schematic Vern posted, you would see that he is using >NTC surge limiters on each light. These minimize startup surges caused by >the very low cold filament resistance of the lamps. > >On the other hand, it depends on the time constants of the NTC surge >limiters vs the time constants of the lamp filaments as to whether these >are effective when in wig-wag mode. > >Dick Tasker A couple of years ago, the effectiveness/value of surge limiters in Wig-Wag systems was discussed here on the List. I went to the workbench and took this trace from the operating current of a 55W halogen lamp flashed at about 2 flashes per second. http://www.aeroelectric.com/Pictures/Curves/Wig_Wag_Currents.jpg Note that the first time the lamp gets power we see the characteristic cold-filament inrush current. However, on subsequent turn-ons, the lamp does not have enough time to cool such that the 7x inrush experience is repeated. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2008
From: "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net>
Subject: Re: AeroElectric-List Digest: 11 Msgs - 09/12/08
Vern, you quoted Carling switch ratings, but if you read further down on the page, you find the following: "Types of Loads: An electric load is the amount of electric power delivered or required at any specific point or points on a system. The requirement originates at the energy consuming equipment of the consumers. More simply put, a load is the piece of equipment you turn on and off. Resistive loads primarily offer resistance to the flow of current. Examples of resistive loads include electric heaters, ranges, ovens, toasters, and irons. If the device is supposed to get hot and doesn't move, it's most likely a resistive load. Inductive loads are usually devices that move and normally include electric magnets, like an electric motor. Examples of inductive loads include such things as power drills, electric mixers, fans, sewing machines, and vacuum cleaners. Transformers also produce inductive loads. High Inrush loads draw a higher amount of current or amperage when first turned on, compared to the amount of current required to continue running. An example of a high inrush load is a light bulb, which may draw 20 or more times its normal operating current when first turned on. This is often referred to as lamp load. Other examples of loads that have high inrush are switching power supplies (capacitive load) and motors (inductive load). . . . . . L & T Ratings An "L" rating denotes the ability of a switch to handle the initial high inrush characteristics of a Tungsten Filament Lamp on AC voltage only. A "T" rating is the equivalent lamp load for DC. H Rating An "H" rating denotes a non-inductive resistive rating. Ratings listed in Carling Technologies' product information may appear with the symbol "H" or with the words "non-inductive" or "resistive". "H" ratings are typically required for switches used in commercial oven applications." Are you sure you are using the switches within their rated specs??????????? My experience using AC rated switches on DC circuits with high inrush currents (landing/taxi lights and strobes in particular) is failure after failure. Eric....this includes ROCKER SWITCHES TOO!.... Cessna rocker switches used in the 70's for example (AC rated "Mr Coffee Maker switches). My $.02 worth...... Scott A Klemptner bmwr606 on Yahoo IM Since there is no reference to DC switch ratings above, does this mean that the DC switches are immune to different load types and L, T, & H ratings? What, may I ask, is the difference between a DC switch and an AC switch??? Roger ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Re: AeroElectric-List Digest: 11 Msgs - 09/12/08
Date: Sep 13, 2008
Hi Scott. The landing and taxi light circuits have inrush current limiters installed, for this very reason. The objective was to save wear and tear on the switches. Steady state draw is about 5 amps. As for the strobe supply, there was some debate on my theory of why this is the worst load in the a/c. My hypothesis is that strobe supplies have a negative voltage-current relationship (negative resistance). If you reduce the voltage to a strobe supply (or, in fact many switchmode power supplies), its current actually increases. Once a switch or terminal fails, this leads to thermal runaway and the results are what I have seen (twice). Not everyone agrees, but I've had this failure twice and Bob has documented another one-- all in the strobe circuits. Thanks for your feedback. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Scott Klemptner Sent: September 13, 2008 8:48 AM Subject: AeroElectric-List: Re: AeroElectric-List Digest: 11 Msgs - 09/12/08 Vern, you quoted Carling switch ratings, but if you read further down on the page, you find the following: "Types of Loads: An electric load is the amount of electric power delivered or required at any specific point or points on a system. The requirement originates at the energy consuming equipment of the consumers. More simply put, a load is the piece of equipment you turn on and off. Resistive loads primarily offer resistance to the flow of current. Examples of resistive loads include electric heaters, ranges, ovens, toasters, and irons. If the device is supposed to get hot and doesn't move, it's most likely a resistive load. Inductive loads are usually devices that move and normally include electric magnets, like an electric motor. Examples of inductive loads include such things as power drills, electric mixers, fans, sewing machines, and vacuum cleaners. Transformers also produce inductive loads. High Inrush loads draw a higher amount of current or amperage when first turned on, compared to the amount of current required to continue running. An example of a high inrush load is a light bulb, which may draw 20 or more times its normal operating current when first turned on. This is often referred to as lamp load. Other examples of loads that have high inrush are switching power supplies (capacitive load) and motors (inductive load). . . . . . L & T Ratings An "L" rating denotes the ability of a switch to handle the initial high inrush characteristics of a Tungsten Filament Lamp on AC voltage only. A "T" rating is the equivalent lamp load for DC. H Rating An "H" rating denotes a non-inductive resistive rating. Ratings listed in Carling Technologies' product information may appear with the symbol "H" or with the words "non-inductive" or "resistive". "H" ratings are typically required for switches used in commercial oven applications." Are you sure you are using the switches within their rated specs??????????? My experience using AC rated switches on DC circuits with high inrush currents (landing/taxi lights and strobes in particular) is failure after failure. Eric....this includes ROCKER SWITCHES TOO!.... Cessna rocker switches used in the 70's for example (AC rated "Mr Coffee Maker switches). My $.02 worth...... Scott A Klemptner bmwr606 on Yahoo IM What if the Hokey-Pokey IS what it's all about? ----- Original Message ---- From: AeroElectric-List Digest Server <aeroelectric-list(at)matronics.com> Sent: Saturday, September 13, 2008 1:55:46 AM ________________________________ Message 7 _____________________________________ From: "Vernon Little" <rv-9a-online(at)telus.net> Subject: RE: AeroElectric-List: Re: Switch problem ***MAJOR UPDATE*** ... > Despite what Bob says, 115 VAC switches should never be used > for LV DC high-current applications. Do what the manufacturer > suggests. That's what's printed on the side of the switch > Bubela. Otherwise you're on your own. > ... > -------- > Eric M. Jones > www.PerihelionDesign.com ... Hi again Eric. Just to comment on what you said: "DC Rule of Thumb For those switches that list an AC voltage rating only, the "DC Rule of Thumb" can be applied for determining the switch's maximum DC current rating. This "rule" states the highest amperage on the switch should perform satisfactorily up to 30 volts DC. For example, a switch which is rated at 10A 250VAC; 15A 125VAC; 3/4HP 125-250VAC, will be likely to perform satisfactorily at 15 amps up to 30 volts DC (VDC)" http://www.carlingtech.com/products/switches/learn_more.asp?page=switch es_am <http://www.carlingtech.com/products/switches/learn_more.asp?page=switc hes_a mp-rating%20> p-rating <http://www.carlingtech.com/products/switches/learn_more.asp?page=switc hes_a mp-rating%20> Therefore, all of my Carling switches are being used according to the manufacturers recommendations. The only gotcha is that the switches are not rated for operating below 0 degrees C. This is probably because the switches are not sealed from condensing moisture. This is not a problem where I live. Vern ________________________________________________________________________________
Date: Sep 13, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: RE: AC vs DC ratings????
>Since there is no reference to DC switch ratings above, does this mean >that the DC switches are immune to different load types and L, T, & H ratings? >What, may I ask, is the difference between a DC switch and an AC switch??? Roger, check the article at: http://www.aeroelectric.com/articles/Switch_Ratings.pdf ALL switches have CAPABILITY in either DC or AC systems. Not all switches are RATED for all applications . . . especially if one limits their enlightenment to the tiny print on the side of the switch. There's not enough room to state the full constellation of a switch's capabilities in that little space. So what's a mother to do? Everyone prints ratings on the device that address the majority of applications where that switch would be used. Service in household and industrial AC line operated appliance. Does the lack of DC numbers mean that the device has no capability in DC operations? Not at all. But in spite of publication of engineering data there are individuals who cannot or choose not to interpret that data in useful ways. Such is the case for the author of the article in Van's Air Force newsletter that prompted the article cited above. Yes, there ARE switch designs that will exhibit optimized service life in DC or AC applications. However, the fact that any given switch is not optimized for one service or the other does not mean that it does not offer useful service in our airplanes. Because of a very low duty-cycle in light aircraft, ratings are only loosely tied to suitability to task. Failure of a switch in our airplanes is more likely to be related to environmental conditions as opposed to service stresses. Bob . . . ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs
Date: Sep 13, 2008
Hi Bob: One more variable: The serious switch failures (the one you analyzed, plus my two) have all been in strobe circuits. We've had some debate about this in the past, but perhaps the analysis of the I-V characteristics of Whelen strobe supply would be in order. I'm curious if there is a combination of elements problem here with switches, terminals and load. When my master switch failed (loose rivets), it manifested itself with alternator overvoltage alarms. The voltage regulator was boosting alternator output to compensate for a voltage drop in the master switch. Normally, you'd suspect a regulator, but it was the switch. The ultimate boilerplate fix was to use the new switch to control a relay that connected the alternator output to the regulator directly (through appropriate fuselink). I'm wondering if a similar band-aid fix for the strobe supply is in order. Perhaps use the switch to control a good automotive relay for this circuit. I don't have a setup for testing a strobe supply myself. Perhaps Whelen has some insight. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Robert L. Nuckolls, III > Sent: September 13, 2008 7:49 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Toggle Switches with Fast-On Tabs > > > > --> > > Let's lay out all the simple ideas behind the design > fabrication and operation of a toggle switch fitted with > fast-on tabs for the purpose of discovering a failure mode > and deducing a remedy. I'll refer the serious students to the > quick-n-dirty sketch at: > > http://aeroelectric.com/Pictures/Switches/Toggle_Switch_with_F > ast-On_Tabs.jpg > > This cross-section will allow us to trace the path of > current flow through the switch as follows: > > Electrons come in via Wire(B) and pass to the fast-on > terminal through wire grip(1) and then on to the fast-on > tab(C) through a high-pressure metal-to-metal > terminal/tab interface(2). Current must then pass > through a high-pressure, metal-to-metal joint(3) to > the contact(D). A low-pressure, metal-to-metal > contact/contact interface(4) carries current to > the teeter-totter(F) via another high-pressure, > metal-to-metal joint(5). > > Current flows through the teeter-totter to a > low-pressure, metal-to-metal sliding joint(6) > at the top of the saddle(G) and then down to > a high-pressure, metal-to-metal joint at the > saddle to rivet interface(7), through the plastic > housing(A) to another high-pressure, metal-to-metal > staked joint(8) and thence on to the fast-on-tab. > > From the fast-on-tab, we find another high-pressure, > metal-to-metal joint at the terminal/tab interface(9) and > finally, another high-pressure, metal-to-metal joint at the > terminal's wire grip(10). > > So if you count them up, there are TEN, conductor- > to-conductor joints that carry current through this > switch installation when the switch is closed. > > By inspection we can deduce that the weakest links > in this conductor chain are at the low-pressure, > metal-to-metal, NON GAS TIGHT joints at (4) and (6). Indeed, > the first switch failure we considered gave us physical > evidence of a failure at (6) that produced a slowly > progressing failure of the switch. This study was described > in detail at: > > http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failu > re/Anatomy_of_a_Switch_Failure.html > > Now we are pondering a demonstrated case of repeated > failures over a period of years in one aircraft. Here > are some of the hard data points: > > (a) All of the switches involved are Carlingswitch > toggles with fast-on tabs. These switches are > an exceedingly mature design that dates back > at least 50 years. IF the root cause of failure > lies with the switches, then it's most likely > a failure of process and not of design. > > (b) All switches showed signs of heating on terminals > that are also on "loose rivets" at (3) or (8). > The fast-on terminals also showed signs of > over-heating in the form of discolored insulators > over the wire-grips. > > (c) While the majority of switch failures were used > in circuits that carry substantial amounts of > current (strobe and landing lights) the first > failure reported was in a master switch that > carries 1A of contactor current and field > current of perhaps 4A max with an in-flight > average current on the order of 1A. > > (d) A photo offered at: > > http://aeroelectric.com/Pictures/Switches/VL_Switch_Failure_2.jpg > > shows distinct signs of over-heating at the > terminal's insulator but no overt signs of > overheating in the metal parts under the terminal. > > I posited the hypothesis a few days ago that IF > the source of heating came from within the switch > and IF temperatures rose high enough to discolor > the terminal's insulation, then temperatures on > the metal parts under the terminal would be high > enough to discolor their surfaces as well. For > example, in the photo at: > > http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/b.jpg > > We see an overheated and loose rivet. We also see > signs of discoloration due to accelerated corrosion > of the fast-on tab adjacent to the rivet head. > These were the overt signs visible from OUTSIDE a > switch that was in serious trouble from heating > effects INSIDE . . . the fast-on-terminal was not > hot enough to distort the shape or color of the > terminal's wire grip. > > Now, the loose rivet phenomenon is easily explained > by a degradation of structural integrity of the > switch's plastic housing(A). Further, since the > failed switches have obviously been running hot, > it follows that the plastic has lost structural > integrity due to heating . . . what is NOT obvious > is whether the initial heat-source came from INSIDE > or OUTSIDE the switch. > > (e) We know that hundreds of thousands of switches using > this design and process are flying on aircraft. IF > there is a problem with the switches, then the BIG > puzzle to be solved is why we find a suite of failures > spanning years of switch production batches and many > flight hours of the subject aircraft. The astute > investigator is obligated to consider all features > of the current path study cited above and either > confirm or discard each of the TEN metal-to-metal > connections as candidates for root cause of > the failures. > > Okay, this dissertation illustrates our of understanding > at the time of this writing. > > It's not only useful but necessary to discount or > confirm the integrity of wire grip joints on the terminals > ESPECIALLY in light of localized heating observed on the > wire-grips of the terminals. This line of investigation is > further encouraged by analysis of the probability of such > concentration of switch failures having root cause in design > or construction of the switches. This consideration alone is > strong suggestion of an ALTERNATIVE EFFECT COMMON TO ALL THE FAILURES. > > On a related topic it has been suggested in the > pages of this forum that Fast-On terminals have > no "Gas Tight" qualities. For clarity let us agree > on the meaning of gas tight. In the dissertation above > I've used the terms high-pressure and metal-to-metal > to describe the interface between two conductors. > By high pressure, I'm speaking of conditions severe > enough to deform metal, i.e. upset its surface or > shape. Keep in mind that this kind of activity > implies pressures in the tens of thousands of pounds > per square inch. In the context of gripping the > strands of wire in the crimp of a terminal, the > term "gas tight" is very descriptive of the > design goal. > > Consider the sketched cross-section of a fast-on > joint which I've posted at: > > http://aeroelectric.com/Pictures/Terminals/Fast-On_Physics.jpg > > We speak to this drawing during the weekend seminars > and point out that most individuals look at a Fast-On > terminal and incorrectly deduce that the spring > forces at the ends of the grips(A) provide an > enduring connection to the tab(B) at the flat interface > between terminal and tab at (2). > > Consider that when you push the Fast-On terminal onto > a tab and pull it off, an examination of the area under > the tips of the grips at (1) will show bright lines > or scratches in the tab metal surface. Tiny? yes. > Pressure? Pushing the terminal onto the tab plows > furrows in the surface of the tab i.e. exerts pressures > in the tens of thousands of PSI. The pressures on the > back side of the interface at (2) are a tiny fraction > of those found on the front side. > > Therefore, I suggest that not only are the interfaces > at (1) gas-tight (due to the intimate contact of terminal > and tab) the interface at (2) is not gas tight. While > (2) may contribute significantly to joint conductivity > when shiny and new, it's contribution ten years hence is > a small fraction of the total. > > Bob . . . > > > > > > ________________________________________________________________________________
Date: Sep 13, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Switch Ratings versus Root Cause of Failure
>Hi Scott. The landing and taxi light circuits have inrush current >limiters installed, for this very reason. The objective was to save wear >and tear on the switches. Steady state draw is about 5 amps. >As for the strobe supply, there was some debate on my theory of why this >is the worst load in the a/c. My hypothesis is that strobe supplies have >a negative voltage-current relationship (negative resistance). If you >reduce the voltage to a strobe supply (or, in fact many switchmode power >supplies), its current actually increases. Once a switch or terminal >fails, this leads to thermal runaway and the results are what I have seen >(twice). > >Not everyone agrees, but I've had this failure twice and Bob has >documented another one-- all in the strobe circuits. It is true that the "negative resistance" or more appropriately "constant power" characteristics of switchmode power supplies may have contributed to the pace of failure. However, in terms of having abused the switch's ratings I'll refer the readers to the photo at: http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/g.jpg This is the working contact in a failed strobe supply switch we examined a few years ago. Note that the contact - the major life-limiting component is almost pristine in comparison with the carnage going on elsewhere . . . http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/e.jpg There's more to this failure analysis stuff than beating on the ratings drum. I'll have to sift through the gray matter but I don't think I have NEVER encountered a failure of a component aboard an aircraft wherein root cause was a failure to observe ratings. It's the FIRST question that should be asked but it's also the easiest concern to put to rest. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Toggle Switches with Fast-On Tabs
> > >Hi Bob: One more variable: The serious switch failures (the one you >analyzed, plus my two) have all been in strobe circuits. We've had some >debate about this in the past, but perhaps the analysis of the I-V >characteristics of Whelen strobe supply would be in order. I'm curious if >there is a combination of elements problem here with switches, terminals and >load. > >When my master switch failed (loose rivets), it manifested itself with >alternator overvoltage alarms. The voltage regulator was boosting >alternator output to compensate for a voltage drop in the master switch. >Normally, you'd suspect a regulator, but it was the switch. The ultimate >boilerplate fix was to use the new switch to control a relay that connected >the alternator output to the regulator directly (through appropriate >fuselink). Yes, that drops the current through the switch to some value on the order of 100 milliamps on the alternator side while leaving the contactor load of about 1A on the battery side. This raise some big red flags suggesting that ratings abuse is not root cause of the failures you've suffered. >I'm wondering if a similar band-aid fix for the strobe supply is in order. >Perhaps use the switch to control a good automotive relay for this circuit. > >I don't have a setup for testing a strobe supply myself. Perhaps Whelen has >some insight. Assuming that root cause turns out to be some form of ratings abuse, then yes . . . the fix is get back within the bounds of ratings. This could include things like buffer relays . . . http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z32K.pdf http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z22-23K.pdf . . . or other adjustment to architecture. But it's not clear to me that we're dealing with a ratings issue. You've had failures in the master switch . . . this is probably the most lightly loaded device on your switch panel! If we are looking at a ratings issue, I think it will be a first in my career of chasing the sources of smoke in airplanes. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2008
From: Dan Reeves <n516dr(at)yahoo.com>
Subject: Toggle Switches with Fast-On Tabs
Perhaps this was already discussed but is it possible that you have a short through the panel itself somewhere?- Kind of like if you lost your engin e ground strap and hit the starter, the current finds a ground through thro ttle cables, etc and fries whatever is in it's path.--Maybe a cigarette lighter style recepticle shorting through the panel and through the switch housings mounted to the panel.- I-wonder if something is vibrating and maybe loosly or intermittantly laying across the fast-on tabs.- Any chan ce of a parking brake cable or something like that making contact with some thing-electrical when it's set or released.- Maybe all irrelevant,,,but just thoughts that came to mind while reading through the recent posts and not hearing of others experiencing similar switch failures. - --- On Sat, 9/13/08, Vernon Little wrote: From: Vernon Little <rv-9a-online(at)telus.net> Subject: RE: AeroElectric-List: Toggle Switches with Fast-On Tabs Date: Saturday, September 13, 2008, 1:58 PM Hi Bob: One more variable: The serious switch failures (the one you analyzed, plus my two) have all been in strobe circuits. We've had some debate about this in the past, but perhaps the analysis of the I-V characteristics of Whelen strobe supply would be in order. I'm curious if there is a combination of elements problem here with switches, terminals an d load. When my master switch failed (loose rivets), it manifested itself with alternator overvoltage alarms. The voltage regulator was boosting alternator output to compensate for a voltage drop in the master switch. Normally, you'd suspect a regulator, but it was the switch. The ultimate boilerplate fix was to use the new switch to control a relay that connected the alternator output to the regulator directly (through appropriate fuselink). I'm wondering if a similar band-aid fix for the strobe supply is in order. Perhaps use the switch to control a good automotive relay for this circuit. I don't have a setup for testing a strobe supply myself. Perhaps Whelen has some insight. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Robert L. Nuckolls, III > Sent: September 13, 2008 7:49 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Toggle Switches with Fast-On Tabs > > > III" > --> > > Let's lay out all the simple ideas behind the design > fabrication and operation of a toggle switch fitted with > fast-on tabs for the purpose of discovering a failure mode > and deducing a remedy. I'll refer the serious students to the > quick-n-dirty sketch at: > > http://aeroelectric.com/Pictures/Switches/Toggle_Switch_with_F > ast-On_Tabs.jpg > > This cross-section will allow us to trace the path of > current flow through the switch as follows: > > Electrons come in via Wire(B) and pass to the fast-on > terminal through wire grip(1) and then on to the fast-on > tab(C) through a high-pressure metal-to-metal > terminal/tab interface(2). Current must then pass > through a high-pressure, metal-to-metal joint(3) to > the contact(D). A low-pressure, metal-to-metal > contact/contact interface(4) carries current to > the teeter-totter(F) via another high-pressure, > metal-to-metal joint(5). > > Current flows through the teeter-totter to a > low-pressure, metal-to-metal sliding joint(6) > at the top of the saddle(G) and then down to > a high-pressure, metal-to-metal joint at the > saddle to rivet interface(7), through the plastic > housing(A) to another high-pressure, metal-to-metal > staked joint(8) and thence on to the fast-on-tab. > > From the fast-on-tab, we find another high-pressure, > metal-to-metal joint at the terminal/tab interface(9) and > finally, another high-pressure, metal-to-metal joint at the > terminal's wire grip(10). > > So if you count them up, there are TEN, conductor- > to-conductor joints that carry current through this > switch installation when the switch is closed. > > By inspection we can deduce that the weakest links > in this conductor chain are at the low-pressure, > metal-to-metal, NON GAS TIGHT joints at (4) and (6). Indeed, > the first switch failure we considered gave us physical > evidence of a failure at (6) that produced a slowly > progressing failure of the switch. This study was described > in detail at: > > http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failu > re/Anatomy_of_a_Switch_Failure.html > > Now we are pondering a demonstrated case of repeated > failures over a period of years in one aircraft. Here > are some of the hard data points: > > (a) All of the switches involved are Carlingswitch > toggles with fast-on tabs. These switches are > an exceedingly mature design that dates back > at least 50 years. IF the root cause of failure > lies with the switches, then it's most likely > a failure of process and not of design. > > (b) All switches showed signs of heating on terminals > that are also on "loose rivets" at (3) or (8). > The fast-on terminals also showed signs of > over-heating in the form of discolored insulators > over the wire-grips. > > (c) While the majority of switch failures were used > in circuits that carry substantial amounts of > current (strobe and landing lights) the first > failure reported was in a master switch that > carries 1A of contactor current and field > current of perhaps 4A max with an in-flight > average current on the order of 1A. > > (d) A photo offered at: > > http://aeroelectric.com/Pictures/Switches/VL_Switch_Failure_2.jpg > > shows distinct signs of over-heating at the > terminal's insulator but no overt signs of > overheating in the metal parts under the terminal. > > I posited the hypothesis a few days ago that IF > the source of heating came from within the switch > and IF temperatures rose high enough to discolor > the terminal's insulation, then temperatures on > the metal parts under the terminal would be high > enough to discolor their surfaces as well. For > example, in the photo at: > > http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/b.jpg > > We see an overheated and loose rivet. We also see > signs of discoloration due to accelerated corrosion > of the fast-on tab adjacent to the rivet head. > These were the overt signs visible from OUTSIDE a > switch that was in serious trouble from heating > effects INSIDE . . . the fast-on-terminal was not > hot enough to distort the shape or color of the > terminal's wire grip. > > Now, the loose rivet phenomenon is easily explained > by a degradation of structural integrity of the > switch's plastic housing(A). Further, since the > failed switches have obviously been running hot, > it follows that the plastic has lost structural > integrity due to heating . . . what is NOT obvious > is whether the initial heat-source came from INSIDE > or OUTSIDE the switch. > > (e) We know that hundreds of thousands of switches using > this design and process are flying on aircraft. IF > there is a problem with the switches, then the BIG > puzzle to be solved is why we find a suite of failures > spanning years of switch production batches and many > flight hours of the subject aircraft. The astute > investigator is obligated to consider all features > of the current path study cited above and either > confirm or discard each of the TEN metal-to-metal > connections as candidates for root cause of > the failures. > > Okay, this dissertation illustrates our of understanding > at the time of this writing. > > It's not only useful but necessary to discount or > confirm the integrity of wire grip joints on the terminals > ESPECIALLY in light of localized heating observed on the > wire-grips of the terminals. This line of investigation is > further encouraged by analysis of the probability of such > concentration of switch failures having root cause in design > or construction of the switches. This consideration alone is > strong suggestion of an ALTERNATIVE EFFECT COMMON TO ALL THE FAILURES. > > On a related topic it has been suggested in the > pages of this forum that Fast-On terminals have > no "Gas Tight" qualities. For clarity let us agree > on the meaning of gas tight. In the dissertation above > I've used the terms high-pressure and metal-to-metal > to describe the interface between two conductors. > By high pressure, I'm speaking of conditions severe > enough to deform metal, i.e. upset its surface or > shape. Keep in mind that this kind of activity > implies pressures in the tens of thousands of pounds > per square inch. In the context of gripping the > strands of wire in the crimp of a terminal, the > term "gas tight" is very descriptive of the > design goal. > > Consider the sketched cross-section of a fast-on > joint which I've posted at: > > http://aeroelectric.com/Pictures/Terminals/Fast-On_Physics.jpg > > We speak to this drawing during the weekend seminars > and point out that most individuals look at a Fast-On > terminal and incorrectly deduce that the spring > forces at the ends of the grips(A) provide an > enduring connection to the tab(B) at the flat interface > between terminal and tab at (2). > > Consider that when you push the Fast-On terminal onto > a tab and pull it off, an examination of the area under > the tips of the grips at (1) will show bright lines > or scratches in the tab metal surface. Tiny? yes. > Pressure? Pushing the terminal onto the tab plows > furrows in the surface of the tab i.e. exerts pressures > in the tens of thousands of PSI. The pressures on the > back side of the interface at (2) are a tiny fraction > of those found on the front side. > > Therefore, I suggest that not only are the interfaces > at (1) gas-tight (due to the intimate contact of terminal > and tab) the interface at (2) is not gas tight. While > (2) may contribute significantly to joint conductivity > when shiny and new, it's contribution ten years hence is > a small fraction of the total. > > Bob . . . > > > > > > =0A=0A=0A ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs
Date: Sep 13, 2008
Hi Dan. Not likely. I checked for for shorts. What I measured was a 2 volt drop across the switch when operating (terminal to terminal). About 12.5V in, 10.5V out. This does not mean I don't have a wiring problem downstream somewhere, but there is no evidence of it, the breaker is intact and the strobes operate. It also means that the switch is dissipation about 14 Watts. No wonder it's hot. Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dan Reeves Sent: September 13, 2008 12:17 PM Subject: RE: AeroElectric-List: Toggle Switches with Fast-On Tabs Perhaps this was already discussed but is it possible that you have a short through the panel itself somewhere? Kind of like if you lost your engine ground strap and hit the starter, the current finds a ground through throttle cables, etc and fries whatever is in it's path. Maybe a cigarette lighter style recepticle shorting through the panel and through the switch housings mounted to the panel. I wonder if something is vibrating and maybe loosly or intermittantly laying across the fast-on tabs. Any chance of a parking brake cable or something like that making contact with something electrical when it's set or released. Maybe all irrelevant,,,but just thoughts that came to mind while reading through the recent posts and not hearing of others experiencing similar switch failures. --- On Sat, 9/13/08, Vernon Little wrote: From: Vernon Little <rv-9a-online(at)telus.net> Subject: RE: AeroElectric-List: Toggle Switches with Fast-On Tabs Date: Saturday, September 13, 2008, 1:58 PM Hi Bob: One more variable: The serious switch failures (the one you analyzed, plus my two) have all been in strobe circuits. We've had some debate about this in the past, but perhaps the analysis of the I-V characteristics of Whelen strobe supply would be in order. I'm curious if there is a combination of elements problem here with switches, terminals and load. When my master switch failed (loose rivets), it manifested itself with alternator overvoltage alarms. The voltage regulator was boosting alternator output to compensate for a voltage drop in the master switch. Normally, you'd suspect a regulator, but it was the switch. The ultimate boilerplate fix was to use the new switch to control a relay that connected the alternator output to the regulator directly (through appropriate fuselink). I'm wondering if a similar band-aid fix for the strobe supply is in order. Perhaps use the switch to control a good automotive relay for this circuit. I don't have a setup for testing a strobe supply myself. Perhaps Whelen has some insight. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Robert L. Nuckolls, III > Sent: September 13, 2008 7:49 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Toggle Switches with Fast-On Tabs > > > III" > --> > > Let's lay out all the simple ideas behind the design > fabrication and operation of a toggle switch fitted with > fast-on tabs for the purpose of discovering a failure mode > and deducing a remedy. I'll refer the serious students to the > quick-n-dirty sketch at: > > http://aeroelectric.com/Pictures/Switches/Toggle_Switch_with_F > ast-On_Tabs.jpg > > This cross-section will allow us to trace the path of > current flow through the switch as follows: > > Electrons come in via Wire(B) and pass to the fast-on > terminal through wire grip(1) and then on to the fast-on > tab(C) through a high-pressure metal-to-metal > terminal/tab interface(2). Current must then pass > through a high-pressure, metal-to-metal joint(3) to > the contact(D). A low-pressure, metal-to-metal > contact/contact interface(4) carries current to > the teeter-totter(F) via another high-pressure, > metal-to-metal joint(5). > > Current flows through the teeter-totter to a > low-pressure, metal-to-metal sliding joint(6) > at the top of the saddle(G) and then down to > a high-pressure, metal-to-metal joint at the > saddle to rivet interface(7), through the plastic > housing(A) to another high-pressure, metal-to-metal > staked joint(8) and thence on to the fast-on-tab. > > From the fast-on-tab, we find another high-pressure, > metal-to-metal joint at the terminal/tab interface(9) and > finally, another high-pressure, metal-to-metal joint at the > terminal's wire grip(10). > > So if you count them up, there are TEN, conductor- > to-conductor joints that carry current through this > switch installation when the switch is closed. > > By inspection we can deduce that the weakest links > in this conductor chain are at the low-pressure, > metal-to-metal, NON GAS TIGHT joints at (4) and (6). Indeed, > the first switch failure we considered gave us physical > evidence of a failure at (6) that produced a slowly > progressing failure of the switch. This study was described > in detail at: > > http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failu > re/Anatomy_of_a_Switch_Failure.html > > Now we are pondering a demonstrated case of repeated > failures over a period of years in one aircraft. Here > are some of the hard data points: > > (a) All of the switches involved are Carlingswitch > toggles with fast-on tabs. These switches are > an exceedingly mature design that dates back > at least 50 years. IF the root cause of failure > lies with the switches, then it's most likely > a failure of process and not of design. > > (b) All switches showed signs of heating on terminals > that are also on "loose rivets" at (3) or (8). > The fast-on terminals also showed signs of > over-heating in the form of discolored insulators > over the wire-grips. > > (c) While the majority of switch failures were used > in circuits that carry substantial amounts of > current (strobe and landing lights) the first > failure reported was in a master switch that > carries 1A of contactor current and field > current of perhaps 4A max with an in-flight > average current on the order of 1A. > > (d) A photo offered at: > > http://aeroelectric.com/Pictures/Switches/VL_Switch_Failure_2.jpg > > shows distinct signs of over-heating at the > terminal's insulator but no overt signs of > overheating in the metal parts under the terminal. > > I posited the hypothesis a few days ago that IF > the source of heating came from within the switch > and IF temperatures rose high enough to discolor > the terminal's insulation, then temperatures on > the metal parts under the terminal would be high > enough to discolor their surfaces as well. For > example, in the photo at: > > http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/b.jpg > > We see an overheated and loose rivet. We also see > signs of discoloration due to accelerated corrosion > of the fast-on tab adjacent to the rivet head. > These were the overt signs visible from OUTSIDE a > switch that was in serious trouble from heating > effects INSIDE . . . the fast-on-terminal was not > hot enough to distort the shape or color of the > terminal's wire grip. > > Now, the loose rivet phenomenon is easily explained > by a degradation of structural integrity of the > switch's plastic housing(A). Further, since the > failed switches have obviously been running hot, > it follows that the plastic has lost structural > integrity due to heating . . . what is NOT obvious > is whether the initial heat-source came from INSIDE > or OUTSIDE the switch. > > (e) We know that hundreds of thousands of switches using > this design and process are flying on aircraft. IF > there is a problem with the switches, then the BIG > puzzle to be solved is why we find a suite of failures > spanning years of switch production batches and many > flight hours of the subject aircraft. The astute > investigator is obligated to consider all features > of the current path study cited above and either > confirm or discard each of the TEN metal-to-metal > connections as candidates for root cause of > the failures. > > Okay, this dissertation illustrates our of understanding > at the time of this writing. > > It's not only useful but necessary to discount or > confirm the integrity of wire grip joints on the terminals > ESPECIALLY in light of localized heating observed on the > wire-grips of the terminals. This line of investigation is > further encouraged by analysis of the probability of such > concentration of switch failures having root cause in design > or construction of the switches. This consideration alone is > strong suggestion of an ALTERNATIVE EFFECT COMMON TO ALL THE FAILURES. > > On a related topic it has been suggested in the > pages of this forum that Fast-On terminals have > no "Gas Tight" qualities. For clarity let us agree > on the meaning of gas tight. In the dissertation above > I've used the terms high-pressure and metal-to-metal > to describe the interface between two conductors. > By high pressure, I'm speaking of conditions severe > enough to deform metal, i.e. upset its surface or > shape. Keep in mind that this kind of activity > implies pressures in the tens of thousands of pounds > per square inch. In the context of gripping the > strands of wire in the crimp of a terminal, the > term "gas tight" is very descriptive of the > design goal. > > Consider the sketched cross-section of a fast-on > joint which I've posted at: > > http://aeroelectric.com/Pictures/Terminals/Fast-On_Physics.jpg > > We speak to this drawing during the weekend seminars > and point out that most individuals look at a Fast-On > terminal and incorrectly deduce that the spring > forces at the ends of the grips(A) provide an > enduring connection to the tab(B) at the flat interface > between terminal and tab at (2). > > Consider that when you push the Fast-On terminal onto > a tab and pull it off, an examination of the area under > the tips of the grips at (1) will show bright lines > or scratches in the tab metal surface. Tiny? yes. > Pressure? Pushing the terminal onto the tab plows > furrows in the surface of the tab i.e. exerts pressures > in the tens of thousands of PSI. The pressures on the > back side of the interface at (2) are a tiny fraction > of those found on the front side. > > Therefore, I suggest that not only are the interfaces > at (1) gas-tight (due to the intimate contact of terminal > and tab) the interface at (2) is not gas tight. While > (2) may contribute significantly to joint conductivity > when shiny and new, it's contribution ten years hence is > a small fraction of the total. > > Bob . . . > > > > > > 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D ________________________________________________________________________________
From: "Joe" <fran5sew(at)banyanol.com>
Subject: Re: Toggle Switches with Fast-On TabsToggle Switches
with Fast-On TabsToggle Switches with Fast-On Tabs
Date: Sep 14, 2008
Vern, That was a good idea to measure the voltage across the switch. By measuring from terminal to terminal, do you mean between the switch terminals and not between the fast-on connectors? Is it possible to measure voltage between the rivet and switch terminal? Just curious. Do you live in a high humidity environment? Whether you do or not, the switches are probably failing because of corrosion. Microswitch makes a military grade sealed switch, the TW Series. It might be expensive but could save you aggravation and failure at critical times. But you have already purchased new switches, maybe next time. Here is another suggestion for next time: buy double-pole switches and connect the two halves in parallel. If one side of the switch fails, the other side will keep you flying. Any heat developed in a double-pole switch will be dissipated over a larger area and thus reduce the temperature rise and slow down the corrosion process. Checking voltage drop across switches could be added to the list of things to do at the annual condition inspection. Many planes could be flying with switches that get warm. The pilot is unaware until there is smoke or until something quits working. Joe ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On TabsToggle Switches
with Fast-On TabsToggle Switches with Fast-On Tabs
Date: Sep 14, 2008
Hi Joe. I measured between switch terminals, but wasn't able to measure the voltage between the terminal and rivet. My aircraft is about 10 miles from the west coast, but there are no signs of corrosion anywhere. Not only is it hangared, but I keep a heater/blower in the cockpit at all times when not flying. I've considered the double-pole idea, but the wiring is a bit of a pain, and without understanding the root cause, I'm not sure I'd go to the effort. Although I had no smoke in the cockpit, my panel was warm. Then, I did the finger test on the switches to see what was up. I think the finger test is just as good as a voltage drop test if access is limited. I hope that a lot of you are out there now poking at switches to see if they have the same symptoms! Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Joe Sent: September 14, 2008 11:20 AM Subject: Re: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Vern, That was a good idea to measure the voltage across the switch. By measuring from terminal to terminal, do you mean between the switch terminals and not between the fast-on connectors? Is it possible to measure voltage between the rivet and switch terminal? Just curious. Do you live in a high humidity environment? Whether you do or not, the switches are probably failing because of corrosion. Microswitch makes a military grade sealed switch, the TW Series. It might be expensive but could save you aggravation and failure at critical times. But you have already purchased new switches, maybe next time. Here is another suggestion for next time: buy double-pole switches and connect the two halves in parallel. If one side of the switch fails, the other side will keep you flying. Any heat developed in a double-pole switch will be dissipated over a larger area and thus reduce the temperature rise and slow down the corrosion process. Checking voltage drop across switches could be added to the list of things to do at the annual condition inspection. Many planes could be flying with switches that get warm. The pilot is unaware until there is smoke or until something quits working. Joe ________________________________________________________________________________
From: "B Tomm" <fvalarm(at)rapidnet.net>
Subject: Toggle Switches with Fast-On TabsToggle Switches
with Fast-On TabsToggle Switches with Fast-On Tabs
Date: Sep 14, 2008
Vern, My RV is no where close to flying yet but I have already purchased Carling toggle switches too. So I will be watching this thread closely and thank you for posting here. I hope that you positively find the root cause and all can benefit. I'm sure Bob will chime in on this but I'm not sure about the theory of using a double pole switch to "spread" the load. A double pole switch may delay the symptom, but it could still occur eventually and possibly very soon after the first set of contacts fail. I guess it depends on what the actual cause of the failure is. Poor crimps, over current heat damage, corrosion, determination due to contact arcing etc. To truly have a secondary (backup) switch, I would think that it would need to be a separate switch that is not used until the primary one fails and is turned off. My opinions only. Your mileage may vary. I hope this failure is positively identified. Bevan _____ From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: Sunday, September 14, 2008 1:55 PM Subject: RE: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Hi Joe. I measured between switch terminals, but wasn't able to measure the voltage between the terminal and rivet. My aircraft is about 10 miles from the west coast, but there are no signs of corrosion anywhere. Not only is it hangared, but I keep a heater/blower in the cockpit at all times when not flying. I've considered the double-pole idea, but the wiring is a bit of a pain, and without understanding the root cause, I'm not sure I'd go to the effort. Although I had no smoke in the cockpit, my panel was warm. Then, I did the finger test on the switches to see what was up. I think the finger test is just as good as a voltage drop test if access is limited. I hope that a lot of you are out there now poking at switches to see if they have the same symptoms! Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Joe Sent: September 14, 2008 11:20 AM Subject: Re: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Vern, That was a good idea to measure the voltage across the switch. By measuring from terminal to terminal, do you mean between the switch terminals and not between the fast-on connectors? Is it possible to measure voltage between the rivet and switch terminal? Just curious. Do you live in a high humidity environment? Whether you do or not, the switches are probably failing because of corrosion. Microswitch makes a military grade sealed switch, the TW Series. It might be expensive but could save you aggravation and failure at critical times. But you have already purchased new switches, maybe next time. Here is another suggestion for next time: buy double-pole switches and connect the two halves in parallel. If one side of the switch fails, the other side will keep you flying. Any heat developed in a double-pole switch will be dissipated over a larger area and thus reduce the temperature rise and slow down the corrosion process. Checking voltage drop across switches could be added to the list of things to do at the annual condition inspection. Many planes could be flying with switches that get warm. The pilot is unaware until there is smoke or until something quits working. Joe href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matro nics.com/Navigator?AeroElectric-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________________________________________________________
Date: Sep 14, 2008
From: Steve Stearns <steve(at)tomasara.com>
Subject: P-Mag and E-Mag safety info from canard-aviators list...
What follows is some critical safety information published by others with a request to please distribute. From my experiences on the canard-aviators listed I believe Marc Z. to be a particularly credible source. My exposure to the other two authors is too limited to have an informed opinion. Steve Stearns Boulder/Longmont, Colorado CSA,EAA,IAC,AOPA,PE,ARRL,BARC (but ignorant none-the-less) Restoring (since 1/07): N45FC O235 Longeze Cothern/Friling CF1 (~1000 Hrs) Flying (since 9/86): N43732 A65 Taylorcraft BC12D ********** Messages from the Canard-aviators list follow ************ 5. Emagair Emag/Pmag Electronic Ignition warning - Part 1 Posted by: "Marc J. Zeitlin" marc_zeitlin(at)alum.mit.edu zeitlinm Sun Sep 14, 2008 5:14 am (PDT) Folks: While I had planned on writing a description and warning of the issues that I had on my trip east in July/August with my electronic ignitions from Emagair (Pmag/Emag), the message that was forwarded to the canard-aviators list by Ric Lee, With a write-up by Gary Cotner describing his crash of his Thorp T-18 due to Emag/Pmag failures has prompted me to accelerate the writing of this warning. So here it is. History (short - a search of the COZY mailing list archives will turn up all my previous posts on this subject): In August of 2004 I purchased a Pmag from Emagair to replace one of my magnetos. During operation over the next months, I had numerous issues with intermittent missing. Brad and Tom at Emagair were extremely good at customer service and replaced my units numerous times whenever I had an issue. Obviously, I was not happy about the problems, but I truly wanted them to succeed - the idea for the units is a great one. By the summer of 2005, after having problems with a unit during my Instrument Instruction, and further problems with replacement units, I threw in the towel, sent the unit back, and got a refund. While replacing the unit with a rebuilt magneto with Ken Miller, we discovered some anomalous wear on the Emagair soft drive gear - Ken was very concerned about this, and I'll get to that issue later. Fast forward to February, 2007. I figured they had had more than enough time (1.5 years) to fix any issues that they had, so I wanted to give Emagair another try. I know that many of you thought that I was insane, and given the rest of this story, you may have very well been correct. But I wanted them to succeed and put Slick/Bendix out of business... At any rate, I got a new generation 3 unit (version 113) and installed it. Within the first month, I had issues with mis-timing, and worked with Emagair to replace the unit. After problems with a second unit, I had been able to run for over a year and 120 hours with no issues whatsoever on the third version 113 unit that I had installed in the spring of 2007. I finally felt like they had the issues licked. After having a magneto failure (reported on list) back in early June of this year (2008), I decided that since I had been having good luck with the Pmag, that I'd get an Emag to go along with it to replace the magneto that had failed. Emagair offered to upgrade my existing Pmag from the version 113 that I had to a version 114 at the same time that they were sending me a new version 114 Emag. Hey - something for nothing - take it, right? I installed both units and flew locally for about 10 hours, taking friends for rides, going places for lunch, etc. No problems at all - engine was running like a top. To Be Continued.... ________________________________________________________________________________
Date: Sep 14, 2008
From: Steve Stearns <steve(at)tomasara.com>
Subject: Part 2 forwarded P-Mag E-Mag Safety info...
************** From Canard Aviators **************** -- Marc J. Zeitlin mailto:marc_zeitlin(at)alum.mit.edu http://www.cozybuilders.org/ Copyright (c) 2008 http://www.mdzeitlin.com/Marc/ Back to top Reply to sender | Reply to group | Reply via web post Messages in this topic (1) 6. Emagair Emag/Pmag Electronic Ignition warning - Part 2 Posted by: "Marc J. Zeitlin" marc_zeitlin(at)alum.mit.edu zeitlinm Sun Sep 14, 2008 5:14 am (PDT) Continued from Part 1: In mid July, 2008, I headed east at the crack of dawn for a two week trip that would take me to Provincetown, MA for a week vacation, a few days in NJ with my mother and sisters for my father's footstone dedication, and then to OSHKOSH with my wife for the obvious reasons and to give the COZY and Canard fora. I took off at 5:30 AM, just as the sun was rising, and headed east. After about an hour and a half, near Kingman, AZ, the engine started running a TINY bit differently - a mag check seemed clean - it was running OK on either EI, but the CHT's had gone up about 10-20 degrees and the power was down a bit. I continued the flight for another 4.5 hours with no issues, landing in Clinton, OK for gas, oil and a bathroom break. Upon runup, I found that one EI was NOT working at all, but I was in the middle of nowhere and had places to be. I'll be writing another story about all of the poor decisions I made on this 36.5 hour trip, and won't address them here, but I'll just describe the events because that's what's germane to the warning. I decided to take off on one EI to get to Ohio, where I'd be staying overnight with Bill Kastenholz. I took off on one EI, climbed over the airport to cruising level, and headed off. About 10 minutes after takeoff, the second EI kicked in and the engine continued running as it had for the previous 4.5 hours - CHT's a little elevated (but not dangerous), power a bit down from normal. 5.5 hours later I landed in Ohio. The next morning, after refueling, I took off (again on one EI - the bad one seemed to not work when cold and work when hot) and flew towards MA. On the way I stopped at Westerly, RI to visit Don Ponciroli but we didn't connect and I called Emagair to talk to them about the issues I was having with the 114 units. I then flew to Norwood, MA to visit Jose Velez, and after a couple of hours on to Provincetown, MA. Each time, I took off on one EI, and each time, the second one kicked in after 10 minutes of warming up. It was apparent that there was a problem with timing, but since it didn't run on the ground when cold, I couldn't adjust it. Emagair sent me a replacement unit in P'town and I replaced it. A test runup indicated that it was running fine, along with the other one. On Friday of that week, I flew down to Brookhaven airport on Long-Island with my son and nephew to bring my nephew home after the vacation week. There was no issue on that flight, and no issue on runup. However, about 7 minutes after taking off from Brookhaven, just about over Orient Point, the engine suddenly started running like crap - RPM's dropped off, CHT's shot through the roof on two cylinders, and power decreased substantially. I brought the power back and made a precautionary landing with my son at Easthaven. On the ground, I called Ken Miller (whom I had spoken to for a few minutes on the ground at Brookhaven), described the symptoms, and he gave me a few things to look for. It turned out that one of the EI's had failed catastrophically, with the timing shifting by a huge amount (no wonder the CHT's were through the roof - it was firing on the intake stroke). Retiming it twice did nothing - it wouldn't hold a timing set. The one that had failed was NOT the replacement unit - it was the second unit that had worked OK on the whole flight east. The replacement unit was working OK. I had to completely unplug the power from the unit in order to get it to stop firing, but once I did, the engine ran OK on the one EI (the replacement unit) that was left. My son and I took off from Easthaven on the one EI and flew uneventfully back to Provincetown. I called Emagair to let them know, and they agreed to send another replacement to NJ, where I would be the next day. I sent my wife to NJ via car instead of having her fly with me, and we made arrangements for her to fly commercial to OSH rather than with me in the plane - I would pick her up when I got there in Appleton. To Be Continued... -- Marc J. Zeitlin mailto:marc_zeitlin(at)alum.mit.edu http://www.cozybuilders.org/ Copyright (c) 2008 http://www.mdzeitlin.com/Marc/ Back to top Reply to sender | Reply to group | Reply via web post Messages in this topic (1) ________________________________________________________________________________
Date: Sep 14, 2008
From: Steve Stearns <steve(at)tomasara.com>
Subject: Part 3 P-Mag E-Mag Safety info....
*************** Message forwarded from Canard Aviators list follows ************************ 7. Emagair Emag/Pmag Electronic Ignition warning - Part 3 Posted by: "Marc J. Zeitlin" marc_zeitlin(at)alum.mit.edu zeitlinm Sun Sep 14, 2008 5:15 am (PDT) Continued from Part 2: In NJ, I received another replacement unit, went out to Caldwell airport and installed it. Checks of both EI's indicated that they were working. The next day I took off and headed to OSH. About 1.5 hours out, over Pennsylvania, one of the EI's started acting up with the same symptoms as the first bad EI - slightly elevated CHT's, timing off a bit, slightly lower power. I navigated from airport to airport, staying as high as was necessary for glide distance, and made it to OSH in 6.5 hours - about 5 after the EI failure. At OSH, I removed the bad EI and took it, along with the other two failed units, to the Emagair booth at OSH. We disassembled the units and found that all three had had catastrophic mechanical failures inside that caused them to not be able to hold timing to any extent at all. Emagair stated that they had not had any failures other than mine of this type, but agreed that this was a design failure. They attributed the failure to excessive vibration caused in some way by my engine, and this plays back to the wear on the removed EI drive gears that Ken Miller and I had seen two years previously. Emagair believed that there was some strange thing going on in my engine that was causing excessive vibration, which beat up the gears and which caused the catastrophic failure of the sensor magnet holder that I had occur three times. I told them that I just needed to fly 11.5 hours more to get home to Tehachapi, and that the plane would be grounded (which it is) for an engine teardown. They did a temporary repair on two of the EI's, which, along with the one in the plane that was still working, gave me three to use for the 11.5 hour flight(s). When I left OSH a couple of days later, I determined that I would also change my flight characteristics to see if I could lessen the stress on the EI's - I never let the RPM's exceed 2500, either in climb or cruise, and I climbed at 140 mph to ensure excessive cooling to the EI. Since the examination of the failed units had pointed to heat and vibration as being the cause of the failures (mechanical - NOT electrical), I wanted to change the heat and vibration signatures of my flying. I was able to fly from OSH to TSP, with one stop in Tucumcari, NM, without any further failures. The plane is grounded and is coming apart; the EI's have been removed and returned, and I've got my refund. Next, I'll describe the issues, the warning, and my recommendations. To Be Continued: -- Marc J. Zeitlin mailto:marc_zeitlin(at)alum.mit.edu http://www.cozybuilders.org/ Copyright (c) 2008 http://www.mdzeitlin.com/Marc/ Back to top Reply to sender | Reply to group | Reply via web post Messages in this topic (1) ________________________________________________________________________________
Date: Sep 14, 2008
From: Steve Stearns <steve(at)tomasara.com>
Subject: Part 4 P-Mag E-Mag Safety info....
************ Following message forwarded from Canard Aviators List ******************* 8. Emagair Emag/Pmag Electronic Ignition warning - Part 4 Posted by: "Marc J. Zeitlin" marc_zeitlin(at)alum.mit.edu zeitlinm Sun Sep 14, 2008 5:16 am (PDT) Continued from Part 3: So what's happening here? As Mr. Cottner and Mr. Read have stated, the Pmag/Emag units lose timing information, firing at arbitrary and sometimes random times. Clearly, this screws up the workings of the engine, sometimes to the point of having no power whatsoever. Mr. Cottner had four failures and lost his airplane because of this failure mode - Mr. Read had to make a precautionary landing, and I had three failures and one precautionary landing. Emagair has issued a SB on both the 113 and 114 units. If you recall, I had timing issues with my 113 units as well. They have instituted a "fix" for the issue, notwithstanding that the 114 mechanical redesign was in part already a "fix" for the problems with the 113 versions. The Emagair units use a small magnet and a hall effect sensor to determine crankshaft position. It's an ingenious solution, because it uses a sensor that can determine crank position within 1 degree, not just when at TDC or within 10 - 30 degrees, as some other EI's do. However, the mounting of the sensor magnet has been flawed from version 113 onward. In version 113, the magnet was epoxied into a metal cup at the end of a shaft. The other end of the shaft had the magneto gear on it and was in intimate contact with the accessory case gears inside the engine, along with the engine oil. This guaranteed that the shaft would get just about as hot as the oil in the accessory case - about 200 F, if not more. Due to the very thin bond line of the epoxy holding the magnet in the cup and the differential CTE's (coefficients of thermal expansion) of the magnet and cup, the thermal stresses in the epoxy can be very large, cracking the epoxy. This would allow the magnet to rotate, thereby losing positional accuracy and timing. After having this failure mode pointed out to them (by me) a year and a half ago, and after having refused my offers to assist them in redesigning the mechanical portion of the units gratis (I am a mechanical engineer with 27 years of experience), Emagair, with an EE but no ME on staff, redesigned the magnet holding portion of the units for the version 114's. They soldered the magnet into a large brass holder, and then glued the holder onto the same shaft that the cup had previously been attached to. They then added two locktited set screws to the holder which applied force to the shaft. There was no flat on the shaft where the set screws touched it. This "fix" was far worse than the disease it was attempting to solve, and is the root cause of the horrible performance of the version 114's under heat and vibration loading. Now that the mass of the brass holder has been made much larger than the mass of the magnet alone, the stresses in the glued bond-line are far higher than previously, and under heat and vibration is guaranteed to fail eventually. The set screws do absolutely nothing, since the CTE of brass is much higher than the CTE of the steel shaft, so as the system gets hot, the set screws don't even touch the shaft. Failure of the glue bond line is sufficient to cause the holder to be able to rotate, with the same mis-timing issues as with a magnet disbond in the version 113 units. Although Emagair has issued an SB, describing a "fix", I do not have ANY confidence in this "fix"'s actually working in the long term. As with Mr. Cotner's warning, I don't believe that the keyway and roll-pin are anything resembling an adequate solution to the magnet mounting problem, which is obviously NOT specific to my engine and/or installation. As more hours are put on these units (I fly 120 hours/year - more than twice the homebuilt average), more will fail, and I have no confidence that this fix will substantially change this situation. Recommendations: My recommendations, based on my opinions and my examination of MANY Emagair unit disassemblies are these: 1) If you are flying with a version 113 or 114 product from Emagair, ground your plane immediately and remove the units. Do NOT fly with them, or with the "fix" described in the SB. It will work for a while, but for how long? 2) If you have a unit that you have purchased but haven't used yet, return it for a refund - do NOT put it on your aircraft and fly it. 3) If you were considering Emagair products for your engine, consider something else - do NOT purchase one and put in on your aircraft. When Emagair have hired a competent mechanical engineering firm to redesign their systems, have FULLY tested the units under O-360 type vibration loads for thousands of hours, and publicly published the results, THEN in may be appropriate to consider these units. Until then, it is not. If Mr. Cotner, Mr. Read, and my experiences with these units put Emagair out of business, and it costs some of you the opportunity to get a refund on your units, I'm sorry for that, but Mr. Cotner was lucky, and relying on luck to keep people alive is not acceptable. Everything that I have written here is either my personal experience, my opinion, or my recommendation based on my opinion. I know that many of you are saying (to yourselves or to others) "I told you so", and you're right - you told me so, but my desire for Emagair to succeed overrode what should have been enough evidence to the contrary. Feel free to write me with "I told you so" messages, if it makes you feel better. I'm happy to address any issues, comments, or questions that anyone may have. Since Emagair never responded to my entreaties to sign an non-disclosure agreement with them, I do not have any responsibility not to explain the inner workings of the units or the problems therein. PLEASE, PLEASE, PLEASE - distribute these messages (and Mr. Cotner's and Mr. Read's) to any and all aviation related mailing lists, fora, and printed newsletters. -- Marc J. Zeitlin mailto:marc_zeitlin(at)alum.mit.edu http://www.cozybuilders.org/ Copyright (c) 2008 http://www.mdzeitlin.com/Marc/ ________________________________________________________________________________
Date: Sep 14, 2008
From: Steve Stearns <steve(at)tomasara.com>
Subject: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner
************ Forwarded from Canard Aviators list **************** Fellow fliers, I received this from a friend on the Bearhawk owners group. I have no dog in this fight but feel it is important for everyone to be aware of. Ric Lee Sandy, Utah --------------------------------------------------------------------------------\ -------------------------------------- Received this as a forward to the Bearhawk group. My name is Gary Cotner Until August 11th I had flown my Thorp T-18 N57GC for twenty years and 1500 hours without any problems. That all changed. Story to follow. I will try to keep it very factual and objective. To all the people on the list and any of the people that you might know that fly with E-MAG or P-MAG on their planes. I want every body to forward this to all concerned. I want this to get out to the aviation community at large. I am going to tell what happened to me. I bought two P-MAGS from E-MAG and put them on the plane prior to going to OSH this year. Flew to OSH and had a good time as usual. On the trip home about 45 minutes out the engine started having an intermittent miss. Was going to Kirksville, MO for fuel, decided to divert to Iowa City, IA. Good thing I did I almost didn't make it. Had to dead stick land there. The left P-MAG had failed completely and the right one was intermittent. I called the E-MAG people and they sent me an E-MAG and P-MAG to replace the defective ones. Put them on and ran the tests 6 times and all was well. Full power runs and mag checks went well. Took off and at about 800 agl the engine started running so rough that I wasn't sure it would maintain altitude. From the past experience I needed to get the plane back on the ground before the engine failed completely. Turned back to runway and was way high to land, slipped and still running out of room to land. Had to divert to a closed runway and still short on room got too slow and pancaked in and totaled the plane. This all because of the E-MAG failures. I called these people about the crash and they were very nonchalant about the problem. Said they weren't sure that I in fact had this failure. Invited them to come to my place and I would run the Engine for them. to prove the problem. It has been 8 days since I asked for an answer and no response. I am going to call tomorrow for an answer as to why they haven't answered my call. The plane is still in good enough condition to run the engine. I have since done this and the E-MAG is intermittent and the engine will back fire when the E-MAG is not firing at its proper time. When these units fail they can fire at random and cause the engine to quit. The stress imposed on the crankshaft is very hard and needs to be addressed as an issue like a sudden stoppage. I reference Dave's comments below and highly recommend that you GROUND YOUR plane until you put an other ignition system on it. In other words don't fly it with E-MAGS or P-MAGS on it. I don't want to see anyone die because of these units as they have an inherent design flaw. The fix that they describe is not a good one,roll pins are very brittle and subject shattering. plus drilling a hole in the shaft creates a stress riser and can lead to failure of the shaft. The shaft should not be able to move at all, the sensor should be keyed to the shaft. This item should be removed from the market in it's present design. ===============================================================================\ == All aircraft that are flying with it need to be grounded until they have a different system on them I think those of you who are running E-mag products need to be aware of my experience over the weekend. I am running dual P-mags on my plane. On the return trip from Waco, TX I developed a rough running engine in cruise at altitude. At first it was just an occasional miss or it felt as if the engine was surging slightly. As time went on the engine ran progressively rougher. Carb heat had no effect. Mag check, right is fine, engine nearly dies on the left. Made a precautionary landing at cape girardeau, engine running terribly, died on rollout, won't restart. When I quit shaking we eventually determined that the left mag had shifted its timing by nearly 180 degrees. At the time of the mag check I did not recognize that the engine would have run fine on the right mag only, I guess I didn't leave it in that position long enough. Anyway I sent both mags to E-mag and this is what happened as I understand it. The mag senses the motor position by a magnet soldered to a brass cap or sleeve that is attached to the drive shaft by a set screw. Somehow it loosened up enough that it rotated on the shaft. This has happened to a small number of others, they were drafting a letter about it when I spoke to Brad on Tuesday. The fix is they are drilling the shaft and installing a roll pin so it cannot move. The repair will be done at no charge. At this time they were not yet considering it a mandatory update. As a side note I can't thank Jarod Callis enough for allowing us to take his T-18 so that we could make it the last hour on home. ________________________________________________________________________________
From: "David & Elaine Lamphere" <dalamphere(at)comcast.net>
Subject: Re: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner
Date: Sep 15, 2008
Thanks to all those concerned for other builder's safety. That's one of the wonderful benefits of subscribing to a group! Sure am glad none of the pilots were killed as a result of these failures. But what a heartache to severely damage a plane that required so much work to build! It almost sounds like one ignition failed causing kick-backs/pre-detonation/vibration that broke the other side! I would like to point out that the fix as I understand it that is posted at EMag's web-site (and I quote): "The correction involves 1) replacing the sensor mount with a lighter one (now only 4 grams), 2) adding a key way to the shaft and the sensor mount, and 3) drilling and roll-pinning the assembly in place." It was mentioned in one of the posts that drilling a hole through the shaft was not acceptable and would create a stress concentration. Please note that the end of the shaft is necked down in diameter and has a keyway slot milled out - that sounds to me like a major stress concentration area also - but is commonly used on magnetos and not a problem to my understanding. What wasn't said at the EMag site was if they still were using epoxy alone to hold the magnet into it's mount. If there's some mechanical shape involved that adds to the integrity of it - good. In the meantime, as I approach finishing of my plane, I'll probably be taking the advice of a good friend and go with one conventional magneto and one (hopefully) fixed EMag product. Also, is this an issue with O-360's and not others? (O-320, O-235,O-200) Dave ________________________________________________________________________________
From: "Tim Andres" <tim2542(at)sbcglobal.net>
Subject: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner
Date: Sep 15, 2008
Dave, if you read Marc Z's account of his problems carefully, you will note that he was UNABLE to turn off the EMAG in flight. If he had been able to turn it off he could have continued on without damaging the engine. Just so you know, it may not be just a matter of turning off the failed Emag and flying safely on one mag. Tim Andres Dave wrote: Thanks to all those concerned for other builder's safety. That's one of the wonderful benefits of subscribing to a group! In the meantime, as I approach finishing of my plane, I'll probably be taking the advice of a good friend and go with one conventional magneto and one (hopefully) fixed EMag product. Also, is this an issue with O-360's and not others? (O-320, O-235,O-200) Dave ________________________________________________________________________________
From: "David & Elaine Lamphere" <dalamphere(at)comcast.net>
Subject: Re: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner
Date: Sep 15, 2008
I appreciate your concern. .. but .. I do not believe that the ignition not shutting off is related to the timing magnet loosening. Either the "P" Lead circuit from his ignition switch was broken, the ignition switch malfunctioning or miswired, or did not switch to running ignition. Think about it.. I know it's a VERY emotional issue to have someting that you trust fail, but let's not give mechanisms sinister minds of their own.. :-) Regards, Dave ----- Original Message ----- From: "Tim Andres" <tim2542(at)sbcglobal.net> Sent: Monday, September 15, 2008 12:12 PM Subject: RE: AeroElectric-List: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner > > > Dave, if you read Marc Z's account of his problems carefully, you will > note > that he was UNABLE to turn off the EMAG in flight. If he had been able to > turn it off he could have continued on without damaging the engine. > Just so you know, it may not be just a matter of turning off the failed > Emag > and flying safely on one mag. > Tim Andres > > Dave wrote: > Thanks to all those concerned for other builder's safety. That's one of > the > wonderful benefits of subscribing to a group! > In the meantime, as I approach finishing of my plane, I'll probably be > taking the advice of a good friend and go with one conventional magneto > and > one (hopefully) fixed EMag product. > > Also, is this an issue with O-360's and not others? (O-320, O-235,O-200) > > Dave > > > ________________________________________________________________________________
From: "F. Tim Yoder" <ftyoder(at)yoderbuilt.com>
Subject: Re: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner
Date: Sep 15, 2008
FYI I installed a Light speed Engineering, Plasma III on my Cont. IO-240 two years ago and have had NO problems. They have been selling units for over 20 yrs. I left one mag on just for safety sake and you still get almost all of the benefits of electronic ignition and save money too. Great report by Marc and forwarded by Steve. Thanks, Tim ----- Original Message ----- From: "David & Elaine Lamphere" <dalamphere(at)comcast.net> Sent: Monday, September 15, 2008 5:59 AM Subject: Re: AeroElectric-List: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner > > Thanks to all those concerned for other builder's safety. That's one of the > wonderful benefits of subscribing to a group! > Sure am glad none of the pilots were killed as a result of these failures. > But what a heartache to severely damage a plane that required so much work > to build! It almost sounds like one ignition failed causing > kick-backs/pre-detonation/vibration that broke the other side! > > I would like to point out that the fix as I understand it that is posted at > EMag's web-site (and I quote): > > "The correction involves 1) replacing the sensor mount with a lighter one > (now only 4 grams), 2) adding a key way to the shaft and the sensor mount, > and 3) drilling and roll-pinning the assembly in place." > > It was mentioned in one of the posts that drilling a hole through the shaft > was not acceptable and would create a stress concentration. Please note that > the end of the shaft is necked down in diameter and has a keyway slot milled > out - that sounds to me like a major stress concentration area also - but is > commonly used on magnetos and not a problem to my understanding. > > What wasn't said at the EMag site was if they still were using epoxy alone > to hold the magnet into it's mount. If there's some mechanical shape > involved that adds to the integrity of it - good. > > In the meantime, as I approach finishing of my plane, I'll probably be > taking the advice of a good friend and go with one conventional magneto and > one (hopefully) fixed EMag product. > > Also, is this an issue with O-360's and not others? (O-320, O-235,O-200) > > Dave > > ________________________________________________________________________________
From: =?iso-8859-1?Q?Mich=E8le_W?= <michele.delsol(at)microsigma.fr>
Subject: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner
Date: Sep 15, 2008
To all, The issues on PMags are a concern as I have planned for 2 of them on a TMX-IO360. As for shutting down the PMags in flight (it seems that Mark Z had a PMag, not an Emag), you can't shut it down by just turning the power off because it will continue generating its own power (above 900 RPM). It does however have a Plead as regular mags have, which will shut it down by grounding. But the Plead has to be connected just as on regular mags. Question, did Marc Z connect his Pleads in such a way that he could shut the PMags down ? In my set up, I have a regular keyed ignition switch just like regular magnetos, connecting the Pleads, plus two breaker switches which feed power to the PMags and LEDS which when lit indicate that the PMags are indeed getting 12 volts. Michle RV8 - trying to get it finished -----Message d'origine----- De: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] De la part de Tim Andres Envoy: lundi 15 septembre 2008 18:13 : aeroelectric-list(at)matronics.com Objet: RE: AeroElectric-List: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner Dave, if you read Marc Z's account of his problems carefully, you will note that he was UNABLE to turn off the EMAG in flight. If he had been able to turn it off he could have continued on without damaging the engine. Just so you know, it may not be just a matter of turning off the failed Emag and flying safely on one mag. Tim Andres Dave wrote: Thanks to all those concerned for other builder's safety. That's one of the wonderful benefits of subscribing to a group! In the meantime, as I approach finishing of my plane, I'll probably be taking the advice of a good friend and go with one conventional magneto and one (hopefully) fixed EMag product. Also, is this an issue with O-360's and not others? (O-320, O-235,O-200) Dave ________________________________________________________________________________
From: "Tim Andres" <tim2542(at)sbcglobal.net>
Subject: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner
Date: Sep 15, 2008
FWIW, a misfiring PMAG/EMAG or plain vanilla mag can break a ring in a second, and hole a piston in little more time than it takes to read this. Can you turn it off that quick? Whether it was wired correctly or not is not the real issue. If it losses time (and it's been well documented that they do) it can do major damage very quickly. Tim Andres -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Michle W Sent: Monday, September 15, 2008 10:00 AM Subject: RE: AeroElectric-List: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner To all, The issues on PMags are a concern as I have planned for 2 of them on a TMX-IO360. As for shutting down the PMags in flight (it seems that Mark Z had a PMag, not an Emag), you can't shut it down by just turning the power off because it will continue generating its own power (above 900 RPM). It does however have a Plead as regular mags have, which will shut it down by grounding. But the Plead has to be connected just as on regular mags. Question, did Marc Z connect his Pleads in such a way that he could shut the PMags down ? In my set up, I have a regular keyed ignition switch just like regular magnetos, connecting the Pleads, plus two breaker switches which feed power to the PMags and LEDS which when lit indicate that the PMags are indeed getting 12 volts. Michle RV8 - trying to get it finished -----Message d'origine----- De: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] De la part de Tim Andres Envoy: lundi 15 septembre 2008 18:13 : aeroelectric-list(at)matronics.com Objet: RE: AeroElectric-List: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner Dave, if you read Marc Z's account of his problems carefully, you will note that he was UNABLE to turn off the EMAG in flight. If he had been able to turn it off he could have continued on without damaging the engine. Just so you know, it may not be just a matter of turning off the failed Emag and flying safely on one mag. Tim Andres Dave wrote: Thanks to all those concerned for other builder's safety. That's one of the wonderful benefits of subscribing to a group! In the meantime, as I approach finishing of my plane, I'll probably be taking the advice of a good friend and go with one conventional magneto and one (hopefully) fixed EMag product. Also, is this an issue with O-360's and not others? (O-320, O-235,O-200) Dave ________________________________________________________________________________
Date: Sep 15, 2008
From: rocket2man <rocket2man(at)isp.com>
Subject: re: B+C alternator problem
This tends to confirm my suspicion that B&C has probably not replaced departed technical staff that used to support this and other products . . . It's true that the "C" version was crafted to offset the effects of an extra-ordinary (outside the Mil-Std-704 envelope) noise situation on the G36 Bonanza. It's also true that your particular installation may be generating some un-anticipated stress that upsets the ov protection. I should point out here . . . AGAIN . . . that this situation is not unique to the so-called "crowbar" shutdown philosophy. It's a situation driven by the dynamics of circuitry that watches for an ov condition and makes a Let-Run/Shut-Down decision. It's a system design and integration problem that must be solved irrespective of the designer's choice for shut-down philosophy. I.e, anyone's OV protection scheme can be similarly "spoofed" into an unnecessary shutdown event. My sense is that B&C is hopeful of keeping this prolem out of their shops . . . so let's do this. The upstream field supply protection should be a 5A breaker. If there's a "fusible" function upstream of the breaker, make it a 24AWG fusible link. Let's get the unit-fuse out of the system. The breaker should be mounted within reach of the pilot. Let's do some flying and see if you can identify the antagonist condition. By the way, I'm assuming you DO have a single point ground behind the panel for all the electro-whizzies? Let's conduct some experiments to see if the noise source can be deduced. If push comes to shove, you can mail me your regulator and I'll modify it here. I think I recall all the things we did to them . . . but it's been 7-10 years ago. Bob . . . Bob - One more data point - before I replaced the blade fuse with a 5 amp C/B, I inserted a 20 amp fuse (the biggest I had handy) and flew it. Used the fuel pump and strobes a couple of times on and off but it did not blow. Then, 20 minutes later without any change in load it blew. Landed, installed another 20 amp blade fuse and flew again. No electrical loads this time until I turned the nav lights on and it was fine. 20 minutes into the flight it blew again. I'm taking the airplane apart again to install the 5 amp C/B. ???? How come this seems to be related to time? I live in the desert and it was 105 F during these flights. JBB ________________________________________________________________________________
Subject: Z13-8B Brown-out battery question
From: "pgroell" <pgroell(at)chello.fr>
Date: Sep 16, 2008
Hello, I have a question about the Z13-8B drawing. http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z13-8B(BrownOutBattery).pdf I understand that the brown-out battery relay opens when pushing the engine start button, disconnecting the brownout battery from the main battery circuit. But I am right to think that in order to have the E-bus energized by the brown-out battery at cranking time, the e-bus alternate feed has to be closed. Or is the alternate feed relay closed by another mean I'm unable to figure out reading the drawing. Thanks for your help. Pascal GROELL www.notreavion.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p 4531#204531 ________________________________________________________________________________
Date: Sep 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Z13-8B Brown-out battery question
> >Hello, >I have a question about the Z13-8B drawing. >http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z13-8B(BrownOutBattery).pdf > >I understand that the brown-out battery relay opens when pushing the >engine start button, disconnecting the brownout battery from the main >battery circuit. >But I am right to think that in order to have the E-bus energized by the >brown-out battery at cranking time, the e-bus alternate feed has to be closed. >Or is the alternate feed relay closed by another mean I'm unable to figure >out reading the drawing. >Thanks for your help. Your analysis is correct. To use this feature for the purpose of preventing reset of e-bus feed systems due to starter inrush brown-out, the e-bus alternate feed switch needs to be closed during starting. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: re: B+C alternator problem
> >This tends to confirm my suspicion that B&C has > probably not replaced departed technical staff that > used to support this and other products . . . > > > > If push comes to shove, you can mail me your regulator > and I'll modify it here. I think I recall all the things > we did to them . . . but it's been 7-10 years ago. > > Bob . . . > >Bob - >One more data point - before I replaced the blade fuse with a 5 amp C/B, I >inserted a 20 amp fuse (the biggest I had handy) and flew it. Used the >fuel pump and strobes a couple of times on and off but it did not >blow. Then, 20 minutes later without any change in load it blew. Landed, >installed another 20 amp blade fuse and flew again. No electrical loads >this time until I turned the nav lights on and it was fine. 20 minutes >into the flight it blew again. I'm taking the airplane apart again to >install the 5 amp C/B. ???? How come this seems to be related to >time? I live in the desert and it was 105 F during these flights. JBB The best hypothesis of the moment suggests that were seeing the effects of time in service for downward drift of trip setting of OV protection, upward drift in total system noise or both. It's equally plausible that the conditions that combine to finally push the OV sensor over the edge are a statistical aggregate of all conditions where they stack up at the edge of the bell curve . . . the conditions that combine to trip the sensor are not frequent but they are random. This is the reason that design goals for OV sense systems use timing values that are substantially above the worst case noise expected in the airplane. The operative term here is 'expected' . . . where we discovered after years of production with one configuration, a particular airplane produced an unexpected combination of stimulus that tripped the OV protection. Folks mistakenly believe that the size of the upstream protection sets the sensitivity of the OV protection. Not so. Increasing the fuse size does not make the system less likely to trip. This is why we recommend that the 5A cb be in included in aircraft that are otherwise protected by fuses. This nuisance tripping phenomenon is not 100.0% predictable. Send me your LR3 and I'll see what I can do to tweak it's setpoint and timing such that it fixes your problem. Bob . . . ________________________________________________________________________________
Date: Sep 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: EV200 circuit
>Still waiting on my contactor sample. What size copper strip are you needing. I found my stash of copper sheet. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 16, 2008
From: "Jeff Page" <jpx(at)Qenesis.com>
Subject: Re: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner Any possibility that grounding the P-Lead would have no effect if the microcontroller was way too busy handling strangely timed interrupts due to the timing sensor bouncing around ? That would depend on whether the P-Lead is a standard input read by the microcontroller, or goes directly to some circuitry that shuts off the spark outputs. Anyone know how the circuirty is designed ? Jeff Page Dream Aircraft Tundra #10 > As for shutting down the PMags in flight (it seems that Mark Z had a PMag, > not an Emag), you can't shut it down by just turning the power off because > it will continue generating its own power (above 900 RPM). It does however > have a Plead as regular mags have, which will shut it down by grounding. But > the Plead has to be connected just as on regular mags. Question, did Marc Z > connect his Pleads in such a way that he could shut the PMags down ? ________________________________________________________________________________
From: "Mike" <mlas(at)cox.net>
Subject: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner
Date: Sep 16, 2008
Tim, You bring up the most important issue of unstable timing. If you time advances at high power it reduces you detonation margin. Their are some important issues here, one you may not recognize detonation, two you may/will damage internal components of your engine, and three permanent damage and/or engine can occur. I have personally rescued a pilot who landed out on a highway in the high country of Arizona. He was very lucky that he found a place to land and no cars were on the road at the time. This could have been a life altering experience. The recap of the failure mode was attributed to heat on the emag/pmags. I'm not sure if that was a correct assessment. I have been running the Lightspeed Plasma III in a dual configuration for over 300 hours. I have had one hard failure with one ignition unite at about 60 hours. Since that repair and upgrade (cooling ports for the hot AZ summers) both unites have worked perfectly. I can assure you that if I ever have a problem with maintaining proper timing that I WILL BECOME A MAGNETO CUSTOMER. Maintaining proper timing is the difference between being a glider and an airplane. An extreme example of improper timing is shown by watching a Top Fuel dragster or funny car go off time. Off timing makes for the BIGGEST explosions in these cars. Check out You Tube. Mike Larkin 31 years flying 30 wrenching 8 years professional wrenching 15 years avionics 5 years professional avionics 21 years professional flying 24 years homebuilding I'm an airplane guy and safety is no. 1 NO COMPROMISING -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Tim Andres Sent: Monday, September 15, 2008 12:45 PM Subject: RE: AeroElectric-List: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner FWIW, a misfiring PMAG/EMAG or plain vanilla mag can break a ring in a second, and hole a piston in little more time than it takes to read this. Can you turn it off that quick? Whether it was wired correctly or not is not the real issue. If it losses time (and it's been well documented that they do) it can do major damage very quickly. Tim Andres 9/5/2008 6:57 AM ________________________________________________________________________________
Subject: Re: E-Mag P-Mag Safety info - Referenced msg from Mr.
Cotner
From: "Marc Zeitlin" <marc_zeitlin(at)alum.mit.edu>
Date: Sep 16, 2008
I joined the matronics lists to be able to respond to a few of the comments posted here, but don't expect to be a regular. At any rate: dalamphere(at)comcast.net wrote: > Either the "P" Lead circuit from his ignition switch was broken, the ignition switch malfunctioning or miswired, or did not switch to running ignition. The Emagair products I had on my engine (one Pmag and one Emag) were both wired with "P" leads, just as the manual explains, and both ignitions were tested with "mag checks" before every flight, including the one in question. In fact, you CAN turn off a Pmag, even with the RPM's above the cutoff of the generator kick-in, with a "P-lead" grounding event, and it had always worked before. The switch worked correctly for 6.5 years prior to and all tests after the failure event, indicating that the switch and wiring were/are working fine. While in the air, I attempted to run off of one EI, then the other EI, then Both EI's, and saw minor differences in operation in the three cases. After landing and UNPLUGGING the power from the failed EI, the engine ran perfectly on the single remaining EI. dalamphere(at)comcast.net wrote: > I do not believe that the ignition not shutting off is related to the timing magnet loosening. I don't know what the firmware in the EI assumes, or how it works, and I don't know what the hardware is doing either. All I can tell you is that when the EI failed due to the magnet slippage and the HUGE change in timing, in this one case the EI would NOT shut itself off via "P-lead" grounding. In all other cases of Emagair product failures that I've had (and it's been a substantial number), they've always shut themselves off when grounded, but in this case, it did not. Believe what you will - I'm certainly more than familiar with believing what I WANT to believe, no matter what the facts of the matter are - just review my usage history with the Emagair products to see that. But the facts are what the facts are. -------- Marc J. Zeitlin marc_zeitlin(at)alum.mit.edu http://www.cozybuilders.org/ http://www.mdzeitlin.com/Marc/ Read this topic online here: http://forums.matronics.com/viewtopic.php?p 4621#204621 ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs **Breaking News**
Date: Sep 16, 2008
Here's some breaking news for those following the burnt-switch thread: I am receipt of a photo from another builder that shows three switches with burnt fast-on tabs! He's identified that two of the switches are the Wig-Wag switch and the Strobe switch. Not sure what the third one is for. I am getting more information and will post it here, including the indentification of the switches and the brands. Compare this new photo: http://www.vx-aviation.com/rv-9a/photos/Electrical/PH_Switches.JPG With the photo from my aircraft: http://www.vx-aviation.com/rv-9a/photos/Electrical/IMG_0935_2.JPG My investigation shows no burned terminals on my Wig-Wag, Landing or Taxi switches, although they did get warm. I do have inrush current limiters on the lighting circuits. My Strobe switch (photo) was toasted, literally, as shown in the second photo. What are the commonalities here? Both are from RV-9As but that's irrelevant. Both aircraft have problems with both the Strobe and Wig-Wag switches (and potentially Landing and Taxi circuits as well). Have yet to identify the switch manufacturers, but evidence is leaning towards brand-independence. Stay tuned. Vern ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs **Breaking News**
Date: Sep 16, 2008
One correction, there are only 2 switches affected in the photo, the third has a black tie-wrap on it! The two circuits that show distress (left to right) are the Wig-Wag and Strobe switches. I have confirmed that the Strobe switch is made by Carling, but the Wig-Wag brand has not been confirmed. Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: September 16, 2008 10:56 AM Subject: AeroElectric-List: Toggle Switches with Fast-On Tabs **Breaking News** Here's some breaking news for those following the burnt-switch thread: I am receipt of a photo from another builder that shows three switches with burnt fast-on tabs! He's identified that two of the switches are the Wig-Wag switch and the Strobe switch. Not sure what the third one is for. I am getting more information and will post it here, including the indentification of the switches and the brands. Compare this new photo: http://www.vx-aviation.com/rv-9a/photos/Electrical/PH_Switches.JPG With the photo from my aircraft: http://www.vx-aviation.com/rv-9a/photos/Electrical/IMG_0935_2.JPG My investigation shows no burned terminals on my Wig-Wag, Landing or Taxi switches, although they did get warm. I do have inrush current limiters on the lighting circuits. My Strobe switch (photo) was toasted, literally, as shown in the second photo. What are the commonalities here? Both are from RV-9As but that's irrelevant. Both aircraft have problems with both the Strobe and Wig-Wag switches (and potentially Landing and Taxi circuits as well). Have yet to identify the switch manufacturers, but evidence is leaning towards brand-independence. Stay tuned. Vern ________________________________________________________________________________
Subject: Toggle Switches with Fast-On Tabs **Breaking News**
Date: Sep 16, 2008
From: "George, Neal E Capt USAF ACC 605 TES/TBM" <Neal.George(at)hurlburt.af.mil>
Vern - I'm betting on sub-standard crimps in high-current circuits. As in not enough wire in the tube to make a proper crimp. For the sake of argument, let's call that a "light" crimp. A light crimp may withstand a tug-test, but then begin to loosen up under the vibration and heat cycles of normal operation. Heat cycles then accelerate deterioration of the joint. Neal ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs **Breaking News**
Date: Sep 16, 2008
I've got some crimps into Bob for F/A, so we can test your theory. It's a bit worrisome, however, that (at least) three persons have had similar failures on their strobe switches, and two on their lamp switches. The other photo I provided is from a builder 3000 miles away, using the same fast-ons and presumably the same crimper. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of George, Neal E Capt USAF ACC 605 TES/TBM > Sent: September 16, 2008 1:01 PM > To: aeroelectric-list(at)matronics.com > Subject: RE: AeroElectric-List: Toggle Switches with Fast-On > Tabs **Breaking News** > > > > USAF ACC > --> 605 TES/TBM" > > Vern - > > I'm betting on sub-standard crimps in high-current circuits. > As in not enough wire in the tube to make a proper crimp. > For the sake of argument, let's call that a "light" crimp. A > light crimp may withstand a tug-test, but then begin to > loosen up under the vibration and heat cycles of normal > operation. Heat cycles then accelerate deterioration of the joint. > > Neal > > > > > > ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs **Breaking News**
Date: Sep 16, 2008
More information from the new photo (friend's airplane). The Wig-Wag switch that is failing is from: <http://www.apem.com/pdf/600H-600NH.pdf> http://www.apem.com/pdf/600H-600NH.pdf. It is a 644H. The wig-wag circuit is flashing an MR16 50W lamp. The HID landing light switch looks fine. Strobe is a Carling switch. More data.... maybe not more information, yet! Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: September 16, 2008 11:27 AM Subject: RE: AeroElectric-List: Toggle Switches with Fast-On Tabs **Breaking News** One correction, there are only 2 switches affected in the photo, the third has a black tie-wrap on it! The two circuits that show distress (left to right) are the Wig-Wag and Strobe switches. I have confirmed that the Strobe switch is made by Carling, but the Wig-Wag brand has not been confirmed. Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: September 16, 2008 10:56 AM Subject: AeroElectric-List: Toggle Switches with Fast-On Tabs **Breaking News** Here's some breaking news for those following the burnt-switch thread: I am receipt of a photo from another builder that shows three switches with burnt fast-on tabs! He's identified that two of the switches are the Wig-Wag switch and the Strobe switch. Not sure what the third one is for. I am getting more information and will post it here, including the indentification of the switches and the brands. Compare this new photo: http://www.vx-aviation.com/rv-9a/photos/Electrical/PH_Switches.JPG With the photo from my aircraft: http://www.vx-aviation.com/rv-9a/photos/Electrical/IMG_0935_2.JPG My investigation shows no burned terminals on my Wig-Wag, Landing or Taxi switches, although they did get warm. I do have inrush current limiters on the lighting circuits. My Strobe switch (photo) was toasted, literally, as shown in the second photo. What are the commonalities here? Both are from RV-9As but that's irrelevant. Both aircraft have problems with both the Strobe and Wig-Wag switches (and potentially Landing and Taxi circuits as well). Have yet to identify the switch manufacturers, but evidence is leaning towards brand-independence. Stay tuned. Vern href="http://www.matronics.com/Navigator?AeroElectric-List">http://www. matro nics.com/Navigator?AeroElectric-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________________________________________________________
Date: Sep 16, 2008
From: Steve Stearns <steve(at)tomasara.com>
Subject: E-Mag P-Mag Safety info - Well reasoned followup part1
Although there have been (as one would expect) a variety of replies to Marc Z's posting on canard-aviators, they were not (my opinion) informative to the same degree that would prompt me to cross-post. However, a posting today by Nick U. (another source that over the time I have been on canard-aviators has struck me as particularly credible) did seem so worthy. I do not anticipate any need to keep people abreast of any more messages on Canard-aviators beyond the posting from Nick U. For those with a particular interest in following the discussion as it continues to develop on this subject please follow it directly at the source: canard-aviators on groups.yahoo.com. Steve Stearns Boulder/Longmont, Colorado CSA,EAA,IAC,AOPA,PE,ARRL,BARC (but ignorant none-the-less) Restoring (since 1/07): N45FC O235 Longeze Cothern/Friling CF1 (~1000 Hrs) Flying (since 9/86): N43732 A65 Taylorcraft BC12D ****************** From canard-aviators ******************** 10. Emag/Pmag Discussion Part 1 <http://groups.yahoo.com/group/canard-aviators/message/46253;_ylc=X3oDMTJyNWFuMzdvBF9TAzk3MzU5NzE1BGdycElkAzI4NTY0ODcEZ3Jwc3BJZAMxNzA1MzQwMDg1BG1zZ0lkAzQ2MjUzBHNlYwNkbXNnBHNsawN2bXNnBHN0aW1lAzEyMjE2MDUwNjM-> Posted by: "U-Nick" unick3(at)gmail.com unick3 <http://profiles.yahoo.com/unick3> Tue Sep 16, 2008 3:02 pm (PDT) Hi all, I wanted to provided an alternate viewpoint to the group discussion concerning Emagair based on my personal experience. In our canard community, I am positive I have the most years/flying hours in front a Pmag and have had many discussions with the owners of Emagair over the years. I can assure all of you, the owners of the company are absolutely committed to the success of Emagair, they listen to each purchasers input, are very open with information, spare no expense to make their electronic ignition the best product possible and try to do right by their customers. I have had a three failures over the years with my Pmag. All the failures were related to the series 112 optical sensor installation which was admittedly early in the development of the product line. In my particular case, I was comfortable early on with the risk I was taking using an unproven product. I just happen to hate mags and wanted something different. Over the years, my confidence with Emagair has grown and I have been lying with a 113 series for about 260 hrs with no problems (2.5 years). My success may be an isolated case in this community, but with over a thousand units out there, Emagair would not still be in business if there was major systemic problems, a high failure rate or they were totally unsafe to fly as some might indicate. This being said, I too share the concern others are expressing with the experience Marc had with his installation. After reading the latest series of emails, I decided to call Emagair to talk with the owner to find out the current news on the magnet cup issue. The reason for my involvement is solely because I am using their product and inadvertently happened to be at Oshkosh this year when Marc brought his failed 114 series Pmag to the Emagair booth and listened to the discussion. After seeing Marc's Emag and listening to his very valid and well reasoned points concerning mass, inertia, mounting system, thermal expansion, adhesive bonding issues, etc, I too could see there was a problem with the how the magnet was mounted on the shaft. Although Emagair had only seen one other case at that time of a loosened magnet assembly they felt this problem needed to be positively resolved. Resolution (part 2) Nick Ugolini Charleston, SC LongEZ-N29TM (2390 hrs), Cozy IV-N199V (restoring), Cozy 540RG (planning stage) Website: http://www.canardzone.com/members/nickugolini/ <http://www.canardzone.com/members/nickugolini/> ________________________________________________________________________________
Date: Sep 16, 2008
From: Steve Stearns <steve(at)tomasara.com>
Subject: E-Mag P-Mag Safety info - Well reasoned followup part2
The second part of Nick U's following message - Steve. *************** from canard-aviators ******************* 11. Emag/Pmag Discussion Part 2 <http://groups.yahoo.com/group/canard-aviators/message/46254;_ylc=X3oDMTJydmg1YzNtBF9TAzk3MzU5NzE1BGdycElkAzI4NTY0ODcEZ3Jwc3BJZAMxNzA1MzQwMDg1BG1zZ0lkAzQ2MjU0BHNlYwNkbXNnBHNsawN2bXNnBHN0aW1lAzEyMjE2MDUwNjM-> Posted by: "U-Nick" unick3(at)gmail.com unick3 <http://profiles.yahoo.com/unick3> Tue Sep 16, 2008 3:02 pm (PDT) The Resolution: Immediately after returning from OSH, a in-house review of the assembly was initiated and a new magnet cup was designed by Emagair to address the concerns of how the magnet assembly is mounted. 1. The mass was significantly reduced from 9.4g to 3.7g. 2. The shaft now have keyway to lock the cup and shaft together. 3. Roll pins have been inserted through the cup and shaft to lock them in place. 4. No adhesive is being used (they are press fit into place) Additionally, a mechanical engineer who is deeply involved with the aviation field, with years of experience working with aviation engines was hired to do a top to bottom review of the mechanics of the ignition system including the magnetic cup assembly. The "fix" (keyway/rollpin) may be overkill (not I am not an expert in this area), but to me it is much more sensible and robust than the previous mounting system. In talking with Emagair the design might change again IF the engineer they hired determines this new mounting method is way too robust and can be further modified for ease of manufacturing and future reliability. The company has issued a service recall on their Pmag/Emag's to replace the magnet assembly. They will tear down the units, inspect them, replace bearings, seals, update electronics, etc free of charge. You only have to pay shipping one way (to them). If you wish to see the old and new cup assemblies, they have posted pictures on thier website under "Service Notes". On a side note, the electronics of the both the Pmag/Emag systems has been very reliable and they have seen very few issues in this area. For my part, I will not ground my plane and will continue to comfortably fly my Pmag with complete confidence. I still think it is a great product and it works very well in my installation. Before anyone has a bone to pick with me for my posts, I want to assure every I am not an advocate or have any involvement with this company. I am just a user of their product and want to provided a fuller picture of this issue based on my discussions with the company and my overall positive experience. That is what this group is all about isn't it? Sharing of information information. Nick Ugolini Charleston, SC LongEZ-N29TM (2390 hrs), Cozy IV-N199V (restoring), Cozy 540RG (planning stage) Website: http://www.canardzone.com/members/nickugolini/ <http://www.canardzone.com/members/nickugolini/> ________________________________________________________________________________
From: "Fergus Kyle" <VE3LVO(at)rac.ca>
Subject:
Date: Sep 17, 2008
" From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> Subject: Re: AeroElectric-List: EV200 circuit >Still waiting on my contactor sample. What size copper strip are you needing. I found my stash of copper sheet. Bob . . ." You're very kind.... The bar is not much longer than 4 inches, so I figured I could use the brass after all. I have 1/8" bar and am fashioning several busses In case the brass won't do the job I plan to duplicate in copper in good time . This Europa doesn't provide much room behind the instruments, so some of it will go six feet aft, including a second battery with a 1/2inch copper pipe as conduit and auxiliary ground. Your 2battery/2alternator circuit refers. Roll on the contractor sample! I will have to choose twixt that and EV200s soon. Cheers, Ferg ________________________________________________________________________________
Date: Sep 17, 2008
From: rocket2man <rocket2man(at)isp.com>
Subject: re:B+C alternator problem
Bob, Thank you for your offer to take a look at my LR-3B. But before I disconnect and send it to you I was poking around last night and noticed the "overvoltage" test switch. I see it on the wiring diagram but what is it or when is it used in a test mode? The reason I ask is the switch appeared to be intermittent (didn't have a good "on-off" feel) and I figure to eliminate it from the list of possible faults I could cut it out of the system or replace it with a new one. Comments? JBB ________________________________________________________________________________
From: "F. Tim Yoder" <ftyoder(at)yoderbuilt.com>
Subject: Re: Igntion Switches------ (Electrical Grimlens)
Date: Sep 17, 2008
Final Final Report, I went flying Sat. and found the same radio transmit problem. I did notice better reception after repairing the bad coax B&C connector. Back at the hanger, I started the wire wiggling again and ultimately found a failed solder joint at a auxiliary mike jack tab. The shrink sleeve was holding it in place so that ground operations were usually ok but contact was intermittent in flight. Will try again this weekend. Tim ----- Original Message ----- From: "F. Tim Yoder" <ftyoder(at)yoderbuilt.com> Cc: Sent: Sunday, September 07, 2008 3:46 PM Subject: Re: Igntion Switches------ (Electrical Grimlens) > {#} Replies are directed back to kisbuilders(at)angus.mystery.com > {#} To reply to the author, write to "F. Tim Yoder" > > FINAL REPORT!!!!!!!! > > After removing the engine ground system, that I ran through the motor mount > via light jumpers, and replacing it with a fat Braded Bonding Strap (#2 AWG) > direct from the engine to the battery negative the movement of the oil > pressure needle was almost eliminated. Not enough to worry about now. > > The radio turned out to be a separate problem. With the engine off, the > battery and radio on I held the PTT and wiggled wires behind the panel. I > was able to recreate the intermittent TX. It turned out to be a defective > BNC connection, faulty assembly! It only lasted 10 years. > > Thanks to all who made suggestions! > > I now have a fresh (clean) and improved ground system. > > Tim N52TY TIME TO GO FLYING > > > ----- Original Message ----- > From: <bakerocb(at)cox.net> > To: ; ; > > Sent: Monday, August 11, 2008 8:24 PM > Subject: Re: Igntion Switches------ (Electrical Grimlens) > > > > {#} Replies are directed back to kisbuilders(at)angus.mystery.com > > {#} To reply to the author, write to > > > > 8/1/2008 > > > > Hello Tim, While I am pondering your situation I will pass your info on to > > the experts on the Matronics aeroelectric-list to see what they can come > up > > with. > > > > 'OC' Says: "The best investment we can make is the effort to gather and > > understand knowledge." > > > > -------------------------------------------------------------- > > > > ----- Original Message ----- > > From: "F. Tim Yoder" <ftyoder(at)yoderbuilt.com> > > To: > > Sent: Monday, August 11, 2008 5:33 PM > > Subject: Re: Igntion Switches------ (Electrical Grimlens) > > > > > > > {#} Replies are directed back to kisbuilders(at)angus.mystery.com > > > {#} To reply to the author, write to "F. Tim Yoder" > > > > > > > > > Hi OC, > > > > > > Two things; > > > > > > First, I flew my TR-1, with a friend, to OSH on the 26th and returned > the > > > 31st. We actually flew into FLD From Mesa AZ (FFZ). Their were > noticabley > > > fewer people in the crowd but the number of planes on the ramp at OSH > and > > > FLD seemed about the same as last year. I flew from Mesa, AZ to FLD, > about > > > 1350 nm and back using 125.1 GAL. in 19.8 HRS. That works out to 6.32 > GPH, > > > not bad! My TR-1 has the IO-240 B1B and I flew at 2550 RPM slightly rich > > > of > > > peak. Also, I have the Light Speed Elect. Ign. on one side. > > > > > > Second, I need some help! > > > A couple of months ago I noticed that after starting my engine the > elect. > > > oil pressure needle would jump when I turned on the Altinator switch, > > > sometimes. Now I notice it doing that every time I start up. also, I > find > > > that ocasionally when the oil temp. is hot the needle will pulse from > > > 45psi > > > to 35psi. Then yesterday, the first flight after returning from OSH, I > > > flew > > > to another local airport for cheeper fuel. My radio transmitted normally > > > leaving however, when I transmitted at the destination airport it was > > > garbled and unreadable. I noticed that the TX symbel was flashing during > > > my > > > transmissions. My reception was clear. After fueling I transmitted and > the > > > radio appeared to be okay. When I got back to my home field my > > > transmissions > > > were garbled again. When I got back to the hanger I determined the > > > following. > > > At idle RPM I could hear a little of the clicking noise during test > > > transmissions. > > > The co-pilot PTT did the same thing. > > > I also noticed that the oil pressure needle would jump when I pushed the > > > PTT. > > > I pulled all the circut breakers one at a time and was unable to > eliminate > > > the problem. > > > With the radio off the oil pressure needle jumps when I cycle the > > > altinator > > > switch. > > > > > > I hope this information might allow you to give me some suggestions on > > > what > > > might be going on. > > > Personally I think it's Voo Doo & Black Magic! > > > > > > Thanks, Tim > > > > > > {#} ----------------------------------------------------+[ > kisbuilders ]+--- > > > > > > > {#} ----------------------------------------------------+[ kisbuilders ]+--- > > ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs **Breaking News**
Date: Sep 17, 2008
OK, here's where I'm heading: Strobe switches are failing. We now have 5 confirmed failures (I've had 2, Bob Nuckolls has done a failure analysis on another, plus three more that I have been advised about recently). In addition, we've had wig-wag and landing/taxi switch failures reported. The most recent information I have from the new case documented in the previous message is that yes, indeed, the switch rivets are loose. It looks like a common contributing factor. Since my replacement switches work fine, but only have a couple of hours of flight time on them, it's tough to tell if we have a problem with certain manufacturers' switches, or an application problem. At this point, I'm betting that we have an application problem due to the high inrush currents that landing/taxi lamps and strobe supplies exhibit. Bob, based on my personal experience and the evidence provided by others, I think it would be a good idea to use high-inrush automotive relays for these circuits, controlled by low-cost switches. Since landing and taxi lights are often wig-wagged, it would be possible to replace the wig-wag flasher with a configuration that only uses relays to handle the high currents in all three modes (wig-wag, taxi, landing). The Strobe circuit would be a simple SPST relay. I know you haven't received my bag-o-bits with the failed switch components and crimps yet so I may be jumping the gun. Nevertheless, there are enough burning switches and terminals out there where we have a potential safety problem that needs to be addressed. Relays may be a band-aid to cover up cheap switch design, but they are designed for this purpose and are very reliable. Thanks, Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: September 16, 2008 1:56 PM Subject: RE: AeroElectric-List: Toggle Switches with Fast-On Tabs **Breaking News** More information from the new photo (friend's airplane). The Wig-Wag switch that is failing is from: <http://www.apem.com/pdf/600H-600NH.pdf> http://www.apem.com/pdf/600H-600NH.pdf. It is a 644H. The wig-wag circuit is flashing an MR16 50W lamp. The HID landing light switch looks fine. Strobe is a Carling switch. More data.... maybe not more information, yet! Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: September 16, 2008 11:27 AM Subject: RE: AeroElectric-List: Toggle Switches with Fast-On Tabs **Breaking News** One correction, there are only 2 switches affected in the photo, the third has a black tie-wrap on it! The two circuits that show distress (left to right) are the Wig-Wag and Strobe switches. I have confirmed that the Strobe switch is made by Carling, but the Wig-Wag brand has not been confirmed. Vern -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: September 16, 2008 10:56 AM Subject: AeroElectric-List: Toggle Switches with Fast-On Tabs **Breaking News** Here's some breaking news for those following the burnt-switch thread: I am receipt of a photo from another builder that shows three switches with burnt fast-on tabs! He's identified that two of the switches are the Wig-Wag switch and the Strobe switch. Not sure what the third one is for. I am getting more information and will post it here, including the indentification of the switches and the brands. Compare this new photo: http://www.vx-aviation.com/rv-9a/photos/Electrical/PH_Switches.JPG With the photo from my aircraft: http://www.vx-aviation.com/rv-9a/photos/Electrical/IMG_0935_2.JPG My investigation shows no burned terminals on my Wig-Wag, Landing or Taxi switches, although they did get warm. I do have inrush current limiters on the lighting circuits. My Strobe switch (photo) was toasted, literally, as shown in the second photo. What are the commonalities here? Both are from RV-9As but that's irrelevant. Both aircraft have problems with both the Strobe and Wig-Wag switches (and potentially Landing and Taxi circuits as well). Have yet to identify the switch manufacturers, but evidence is leaning towards brand-independence. Stay tuned. Vern href="http://www.matronics.com/Navigator?AeroElectric-List">http://www. matro nics.com/Navigator?AeroElectric-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c href="http://www.matronics.com/Navigator?AeroElectric-List">http://www. matro nics.com/Navigator?AeroElectric-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________________________________________________________
Date: Sep 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: E-Mag P-Mag Safety info
I've been out of town for a couple of days an we don't have handy access to e-mail set up yet in M.L. Some thoughts on the current e-mag kerfuffle: I spoke at length with Brad at Emagair yesterday. He was quite willing to "bare his soul" as it were and made me privy to some facts that will probably never be put out for public consumption. But suffice it to say the following: The unique failure mode that began this thread is an rare event in the constellation of delivered product. It involves a combination of things, some of which may never be fully quantified because the combination is unique to the as-installed system. Theses are exceedingly difficult to access for measurement, analysis and deduction of root cause. 95% of all my experiences in such matters have shown that the fastest route to customer satisfaction is to add robustness by redesign. After all, how difficult is it to get a grip on an aspirin sized magnet? The problem is centered on a limited segment of production as outlined in this document published on Emag's website: http://emagair.com/E-MAG%20Service%20Bulletin%203.pdf The mechanical issues surrounding attachment of the position sensor magnet have been addressed and the new attach methodology has been implemented in production, all units returned for any kind of service are being upgraded. Details of the new magnet mount are shown here: http://emagair.com/sensor%20SB.htm There are countless situations in the history of emerging technologies that progress is measured in more-steps-forward- than-steps-back. We rely on lessons learned, sifting of the simple-ideas for optimum design, test to the best of our ability and then go to market. Ultimate success or failure is driven by the combination of technical prowess, manufacturing skill and honorable behavior in the marketplace. It's a mystery as to why a small number of installations have experienced a cluster of failures. After all, this configuration has been in the marketplace for over 13 months but the cluster of failures surfaced in the past few months. As I outlined above, it's probably not in the stars that a detailed investigation will or even can be conducted to ascertain the combination of stresses and limits that produced the failures. There are individuals who have complained that their offered expertise and talents for deducing root cause and/or remedy were rebuffed. Any of you that have been in business will understand that it is not a good idea to engage individuals for problem solving that have too many dogs in the hunt. The fact that capable and perhaps very useful talents were not utilized is not evidence of irresponsible or dishonorable behavior on the part of Emag. There are individuals who for whatever reasons will suggest there is great cause for contemplation, discussion and perhaps even a call to action for dealing with such matters. The discussions have already filled many keyboard-hours of participants on the 'net. A common thread that runs through much of the discussions I've read is the lack of data from original sources on what happened and what's being done to fix it. If anyone has personal concerns, call Emag and talk to Brad or Tom. I've visited their facility and have exchanged email and telephone conversations with them. I have no reason to believe they're not exercising due diligence in application of appropriate skills, talent and technology to address a "step backwards" in the evolution of their product. I also find no evidence of dishonorable behavior on their part. Finally, I'll remind readers of this List of a suggestion I made some years ago as the Emag products first emerged. When you buy an engine with mags, you're not likely to get much if any rebate for leaving the mags off. Given that 90+ percent of performance gains for EI come with the installation of but one system, how about running one of your mags in parallel with one Emag? When the first mag craps, put the second mag on. Don't install dual Emags until you've "used up" both mags. This philosophy will allow you to exploit performance gains offered while insulting yourself from the inevitable effects of steps-back during the development of any product. This mixed-technology approach to exemplary system reliability is a tried and proven technique. I'm not suggesting that discussions on this topic should not continue. I do suggest that for individuals who are gravely concerned about their own projects AVOID making a decision based on 'net-babble. Yes, until you access original-source-data or you are reading the analysis from a learned writer that has access to original-source-data, it's ALL 'net-babble. Keep in mind too that folks who have experienced failures are not sources of original data that goes beyond the facts of their experience. Someone who suffers a stroke may have a great deal to say about their experience without knowing a thing about the simple-ideas that caused it. Their telling of the story has the effect of raising fear of stroke on the part of listeners . . . but adds nothing to an understanding of how risk for a similar experience can be reduced. Call Emag and if push comes to shove, run a Magneto/Emag combination for awhile. Bottom line is that the sky is not falling. Bob . . . ________________________________________________________________________________
Date: Sep 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: re:B+C alternator problem
> >Bob, >Thank you for your offer to take a look at my LR-3B. But before I >disconnect and send it to you I was poking around last night and >noticed the "overvoltage" test switch. I see it on the wiring diagram but >what is it or when is it used in a test mode? Yeah, I included that in the original design as a pre-flight test item . . . but in later years we decided that testing every flight wasn't necessary. I think the instructions now call for periodic testing by means of a temporary jumper or perhaps a push-button in an off-the-panel location. > The reason I ask is the switch appeared to be intermittent (didn't have > a good "on-off" feel) and I figure to eliminate it from the list of > possible faults I could cut it out of the system or replace it with a new one. Aha! An installed switch. Yes, that COULD be a source of your problems. Replacing it would be a valuable experiment. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: re: Brad's reply on P-lead switch functionality
Received a reply from Brad on functionality of the p-lead switch in Emag products: "Grounding the p-lead 1) sends a status signal to the processor (telling it to stop firing), and 2) disables the driver chips (so they can't fire)." Bob . . . ---------------------------------------- > > >Jeff, although a good point to bring up, I highly doubt that such an >important function would go to the microprocessor, except as a status input. >Surely it would go to a hard wired shut off circuit outside the micro >to guarantee outside control without software being involved. If it >didn't, it would be a major design error. However, all of these >details are most likely proprietary data, and only Emagair would know. > >Simon -------------------------------------- >Subject: AeroElectric-List: Re: E-Mag P-Mag Safety info - Referenced >msg from Mr. Cotner > > >Any possibility that grounding the P-Lead would have no effect if the >microcontroller was way too busy handling strangely timed interrupts >due to the timing sensor bouncing around ? That would depend on >whether the P-Lead is a standard input read by the microcontroller, or >goes directly to some circuitry that shuts off the spark outputs. >Anyone know how the circuirty is designed ? > >Jeff Page >Dream Aircraft Tundra #10 ________________________________________________________________________________
Date: Sep 18, 2008
From: "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net>
Subject: re: Brad's reply on P-lead switch functionality
Received a reply from Brad on functionality of the p-lead switch in Emag products: "Grounding the p-lead 1) sends a status signal to the processor (telling it to stop firing), and 2) disables the driver chips (so they can't fire)." Bob . . . Is the driver chip disable signal a "hard wired" signal to the drivers, or is it a signal derived through the processor? It could be a problem if it is through the processor, and the processor gets hung up by some inputs with errors. Roger ________________________________________________________________________________
From: "S. Ramirez" <simon(at)synchronousdesign.com>
Subject: re: Brad's reply on P-lead switch functionality
Date: Sep 18, 2008
Thank you, Bob, for publicly responding. This redundant method of shutting off the fire signal is a good and proven way of doing it, i.e. better than simply shutting off the drivers as I said below. Now the only question is why Marc Zeitlin's engine didn't quit firing? He claims he tried to shut it off and the P-Lead was connected. Could there have been an intermittent open in his wiring or possibly a problem in the PMag electronics, possibly related to temperature or vibration? Simon Copyright 2008 -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, September 18, 2008 11:36 AM Subject: AeroElectric-List: re: Brad's reply on P-lead switch functionality Received a reply from Brad on functionality of the p-lead switch in Emag products: "Grounding the p-lead 1) sends a status signal to the processor (telling it to stop firing), and 2) disables the driver chips (so they can't fire)." Bob . . . ---------------------------------------- > > >Jeff, although a good point to bring up, I highly doubt that such an >important function would go to the microprocessor, except as a status input. >Surely it would go to a hard wired shut off circuit outside the micro >to guarantee outside control without software being involved. If it >didn't, it would be a major design error. However, all of these >details are most likely proprietary data, and only Emagair would know. > >Simon ________________________________________________________________________________
Date: Sep 18, 2008
From: "Jeff Page" <jpx(at)Qenesis.com>
Subject: Re: Toggle Switches with Fast-On Tabs
Any chance that unsupported wires are vibrating in flight and helping to loosen the rivets, which then heat up from poor contact ? Jeff Page Dream Aircraft Tundra #10 > From: "Vernon Little" <rv-9a-online(at)telus.net> > The most recent information I have from the new case documented in the > previous message is that yes, indeed, the switch rivets are loose. It > looks like a common contributing factor. ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
Hi Jeff. This came up previously, and the answer is that they are all supported properly. It appears that the underlying cause may be a combination of high inrush currents and "economy" switches that start the thermal runaway cycle: switch heating causes rivets to loosen; loose rivets cause more switch heating. With the exception of one switch, all of the problems have been in the strobe and landing/taxi light circuits in multiple aircraft. I'm hoping for more results from the list members who are checking their switches for damage or overheating using the finger test. Thanks, Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Jeff Page > Sent: September 18, 2008 11:08 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > Any chance that unsupported wires are vibrating in flight and > helping > to loosen the rivets, which then heat up from poor contact ? > > Jeff Page > Dream Aircraft Tundra #10 > > > From: "Vernon Little" <rv-9a-online(at)telus.net> > > The most recent information I have from the new case > documented in the > > previous message is that yes, indeed, the switch rivets are > loose. It > > looks like a common contributing factor. > > > > > > ________________________________________________________________________________
From: "B Tomm" <fvalarm(at)rapidnet.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
Vern, I understand that your switches were "properly" supported. Just wondering if the wire "support" needs to be more substantial than usual if there are large gauge wires involved, such as would be expected for landing light circuits? My thinking is that the larger the wire, the more momentum it has when vibrating due to it's mass. Secondly, maybe I've missed something here, but concerning the "loose" rivets. It is thought that the rivets are loose because of overheating, or vibration (with a heavy wire attached), or poor manufacturing process or what? Bevan -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: Thursday, September 18, 2008 11:54 AM Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs --> Hi Jeff. This came up previously, and the answer is that they are all supported properly. It appears that the underlying cause may be a combination of high inrush currents and "economy" switches that start the thermal runaway cycle: switch heating causes rivets to loosen; loose rivets cause more switch heating. With the exception of one switch, all of the problems have been in the strobe and landing/taxi light circuits in multiple aircraft. I'm hoping for more results from the list members who are checking their switches for damage or overheating using the finger test. Thanks, Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of > Jeff Page > Sent: September 18, 2008 11:08 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > Any chance that unsupported wires are vibrating in flight and helping > to loosen the rivets, which then heat up from poor contact ? > > Jeff Page > Dream Aircraft Tundra #10 > > > From: "Vernon Little" <rv-9a-online(at)telus.net> The most recent > > information I have from the new case > documented in the > > previous message is that yes, indeed, the switch rivets are > loose. It > > looks like a common contributing factor. > > > > > > ________________________________________________________________________________
Date: Sep 18, 2008
From: Ken <klehman(at)albedo.net>
Subject: Re: Toggle Switches with Fast-On Tabs
All my Carlings seem fine and run cold. 2+ years, 220 hours, AMP PIDG connectors, Aeroflash strobes, 35 watt wigwag lights. Ken snip > I'm hoping for more results from the list members who are checking their > switches for damage or overheating using the finger test. > > Thanks, Vern > ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
Good datapoint, thanks. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Ken > Sent: September 18, 2008 1:14 PM > To: aeroelectric-list(at)matronics.com > Subject: Re: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > All my Carlings seem fine and run cold. 2+ years, 220 hours, AMP PIDG > connectors, Aeroflash strobes, 35 watt wigwag lights. > Ken > > snip > > I'm hoping for more results from the list members who are checking > > their switches for damage or overheating using the finger test. > > > > Thanks, Vern > > > > > > > ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
Hey Bevan. Based on the evidence, the Strobe switch is failing in multiple aircraft, and the Wig-Wag/Ldg/Taxi lights have a couple of failures. No evidence in these aircraft of other switches with problems. This tends to rule out an installation problem. The loose rivets are a both a cause and an effect. Some of the Carling switches have somewhat loose rivets when new. After the switch is fried, they are looser and the terminals are discolored. If vibration is the problem, there are many other places in the aircraft that would show overheating (wig-wag flasher, terminal block at wing root and so on). None do. I think the obvious problem is the switches are being stressed by overload, and these stresses are leading to looser rivets and further overheating. I have new/different switches now, but if I have a failure again, I'm installing relays. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of B Tomm > Sent: September 18, 2008 1:05 PM > To: aeroelectric-list(at)matronics.com > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > > Vern, > > I understand that your switches were "properly" supported. > Just wondering if the wire "support" needs to be more > substantial than usual if there are large gauge wires > involved, such as would be expected for landing light > circuits? My thinking is that the larger the wire, the more > momentum it has when vibrating due to it's mass. > > Secondly, maybe I've missed something here, but concerning > the "loose" rivets. It is thought that the rivets are loose > because of overheating, or vibration (with a heavy wire > attached), or poor manufacturing process or what? > > Bevan > > > > > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Vernon Little > Sent: Thursday, September 18, 2008 11:54 AM > To: aeroelectric-list(at)matronics.com > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > --> > > Hi Jeff. This came up previously, and the answer is that > they are all supported properly. It appears that the > underlying cause may be a combination of high inrush currents > and "economy" switches that start the thermal runaway cycle: > switch heating causes rivets to loosen; loose rivets cause > more switch heating. > > With the exception of one switch, all of the problems have > been in the strobe and landing/taxi light circuits in > multiple aircraft. > > I'm hoping for more results from the list members who are > checking their switches for damage or overheating using the > finger test. > > Thanks, Vern > > > -----Original Message----- > > From: owner-aeroelectric-list-server(at)matronics.com > > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of > > Jeff Page > > Sent: September 18, 2008 11:08 AM > > To: aeroelectric-list(at)matronics.com > > Subject: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > > > > > > > Any chance that unsupported wires are vibrating in flight > and helping > > to loosen the rivets, which then heat up from poor contact ? > > > > Jeff Page > > Dream Aircraft Tundra #10 > > > > > From: "Vernon Little" <rv-9a-online(at)telus.net> The most recent > > > information I have from the new case > > documented in the > > > previous message is that yes, indeed, the switch rivets are > > loose. It > > > looks like a common contributing factor. > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "Tom Costanza" <Tom(at)costanzaandassociates.com>
Subject: Re: Toggle Switches with Fast-On Tabs **Breaking News**Toggle
Switches with Fast-On Tabs Toggle Switches with Fast-On Tabs Toggle Switches with Fast-On Tabs **Breaking
Date: Sep 18, 2008
Vern, Don't you think that if it was an application problem that we'd be hearing from people on a few orders of magnitude more than we have? There must be several hundred people using these switches in these circuits. No?? -Tom ________________________________________________________________________________
From: "F. Tim Yoder" <ftyoder(at)yoderbuilt.com>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
Is their a manufacturing date or any number on the switches that would let you identify a bad batch of switches? Sounds like some switches come with loose rivets and some don't have loose rivets. Is that correct? The manufacture should be able to tell you if loose rivets are.acceptable. Tim ----- Original Message ----- From: "Vernon Little" <rv-9a-online(at)telus.net> Sent: Thursday, September 18, 2008 1:57 PM Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > Hey Bevan. Based on the evidence, the Strobe switch is failing in multiple > aircraft, and the Wig-Wag/Ldg/Taxi lights have a couple of failures. No > evidence in these aircraft of other switches with problems. This tends to > rule out an installation problem. The loose rivets are a both a cause and > an effect. Some of the Carling switches have somewhat loose rivets when > new. After the switch is fried, they are looser and the terminals are > discolored. > > If vibration is the problem, there are many other places in the aircraft > that would show overheating (wig-wag flasher, terminal block at wing root > and so on). None do. > > I think the obvious problem is the switches are being stressed by overload, > and these stresses are leading to looser rivets and further overheating. I > have new/different switches now, but if I have a failure again, I'm > installing relays. > > Vern > > > > -----Original Message----- > > From: owner-aeroelectric-list-server(at)matronics.com > > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > > Behalf Of B Tomm > > Sent: September 18, 2008 1:05 PM > > To: aeroelectric-list(at)matronics.com > > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > > > > > > > > Vern, > > > > I understand that your switches were "properly" supported. > > Just wondering if the wire "support" needs to be more > > substantial than usual if there are large gauge wires > > involved, such as would be expected for landing light > > circuits? My thinking is that the larger the wire, the more > > momentum it has when vibrating due to it's mass. > > > > Secondly, maybe I've missed something here, but concerning > > the "loose" rivets. It is thought that the rivets are loose > > because of overheating, or vibration (with a heavy wire > > attached), or poor manufacturing process or what? > > > > Bevan > > > > > > > > > > -----Original Message----- > > From: owner-aeroelectric-list-server(at)matronics.com > > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > > Behalf Of Vernon Little > > Sent: Thursday, September 18, 2008 11:54 AM > > To: aeroelectric-list(at)matronics.com > > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > --> > > > > Hi Jeff. This came up previously, and the answer is that > > they are all supported properly. It appears that the > > underlying cause may be a combination of high inrush currents > > and "economy" switches that start the thermal runaway cycle: > > switch heating causes rivets to loosen; loose rivets cause > > more switch heating. > > > > With the exception of one switch, all of the problems have > > been in the strobe and landing/taxi light circuits in > > multiple aircraft. > > > > I'm hoping for more results from the list members who are > > checking their switches for damage or overheating using the > > finger test. > > > > Thanks, Vern > > > > > -----Original Message----- > > > From: owner-aeroelectric-list-server(at)matronics.com > > > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of > > > Jeff Page > > > Sent: September 18, 2008 11:08 AM > > > To: aeroelectric-list(at)matronics.com > > > Subject: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > > > > > > > > > > > > > Any chance that unsupported wires are vibrating in flight > > and helping > > > to loosen the rivets, which then heat up from poor contact ? > > > > > > Jeff Page > > > Dream Aircraft Tundra #10 > > > > > > > From: "Vernon Little" <rv-9a-online(at)telus.net> The most recent > > > > information I have from the new case > > > documented in the > > > > previous message is that yes, indeed, the switch rivets are > > > loose. It > > > > looks like a common contributing factor. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
If you look back in the thread, I identified the date code of my switches, and the one that Bob wrote his article on. No codes for the other failures reported yet. We have not seen any correlation, plus one switch was made by another vendor altogether. I returned a failed Carling master switch for failure analysis to the vendor, but never heard anything. It had loose rivets as well, but was not a heavily loaded switch. Since I never heard anything, I've gone public on this list to get some collective wisdom working on the problem. I'm convinced that loose rivets are a big problem. I'm an electrical engineer, not a mechanical engineer, but it's pretty obvious that the rivets should not be loose. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of F. Tim Yoder > Sent: September 18, 2008 4:52 PM > To: aeroelectric-list(at)matronics.com > Subject: Re: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > --> > > Is their a manufacturing date or any number on the switches > that would let you identify a bad batch of switches? Sounds > like some switches come with loose rivets and some don't have > loose rivets. Is that correct? > > The manufacture should be able to tell you if loose rivets > are.acceptable. > > Tim > > ----- Original Message ----- > From: "Vernon Little" <rv-9a-online(at)telus.net> > To: > Sent: Thursday, September 18, 2008 1:57 PM > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > > > Hey Bevan. Based on the evidence, the Strobe switch is failing in > multiple > > aircraft, and the Wig-Wag/Ldg/Taxi lights have a couple of > failures. > > No evidence in these aircraft of other switches with > problems. This > > tends to rule out an installation problem. The loose rivets are a > > both a cause and an effect. Some of the Carling switches have > > somewhat loose rivets when new. After the switch is fried, > they are > > looser and the terminals are discolored. > > > > If vibration is the problem, there are many other places in the > > aircraft that would show overheating (wig-wag flasher, > terminal block > > at wing root and so on). None do. > > > > I think the obvious problem is the switches are being stressed by > overload, > > and these stresses are leading to looser rivets and further > > overheating. > I > > have new/different switches now, but if I have a failure again, I'm > > installing relays. > > > > Vern > > > > > > > > > -----Original Message----- > > > From: owner-aeroelectric-list-server(at)matronics.com > > > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of B > > > Tomm > > > Sent: September 18, 2008 1:05 PM > > > To: aeroelectric-list(at)matronics.com > > > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On > > > Tabs > > > > > > > > > > > > > > > > > > Vern, > > > > > > I understand that your switches were "properly" supported. Just > > > wondering if the wire "support" needs to be more substantial than > > > usual if there are large gauge wires involved, such as would be > > > expected for landing light circuits? My thinking is that > the larger > > > the wire, the more momentum it has when vibrating due to > it's mass. > > > > > > Secondly, maybe I've missed something here, but concerning the > > > "loose" rivets. It is thought that the rivets are loose > because of > > > overheating, or vibration (with a heavy wire attached), or poor > > > manufacturing process or what? > > > > > > Bevan > > > > > > > > > > > > > > > -----Original Message----- > > > From: owner-aeroelectric-list-server(at)matronics.com > > > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of > > > Vernon Little > > > Sent: Thursday, September 18, 2008 11:54 AM > > > To: aeroelectric-list(at)matronics.com > > > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On > > > Tabs > > > > > > --> > > > > > > Hi Jeff. This came up previously, and the answer is that > they are > > > all supported properly. It appears that the underlying > cause may be > > > a combination of high inrush currents and "economy" switches that > > > start the thermal runaway cycle: switch heating causes rivets to > > > loosen; loose rivets cause more switch heating. > > > > > > With the exception of one switch, all of the problems > have been in > > > the strobe and landing/taxi light circuits in multiple aircraft. > > > > > > I'm hoping for more results from the list members who are > checking > > > their switches for damage or overheating using the finger test. > > > > > > Thanks, Vern > > > > > > > -----Original Message----- > > > > From: owner-aeroelectric-list-server(at)matronics.com > > > > [mailto:owner-aeroelectric-list-server(at)matronics.com] > On Behalf Of > > > > Jeff Page > > > > Sent: September 18, 2008 11:08 AM > > > > To: aeroelectric-list(at)matronics.com > > > > Subject: AeroElectric-List: Re: Toggle Switches with > Fast-On Tabs > > > > > > > > > > > > > > > > > > > > > > > Any chance that unsupported wires are vibrating in flight > > > and helping > > > > to loosen the rivets, which then heat up from poor contact ? > > > > > > > > Jeff Page > > > > Dream Aircraft Tundra #10 > > > > > > > > > From: "Vernon Little" <rv-9a-online(at)telus.net> The > most recent > > > > > information I have from the new case > > > > documented in the > > > > > previous message is that yes, indeed, the switch rivets are > > > > loose. It > > > > > looks like a common contributing factor. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs **Breaking News**Toggle
Switches with Fast-On Tabs Toggle Switches with Fast-On Tabs Toggle Switches with Fast-On Tabs **Breaking
Date: Sep 18, 2008
Hi Tom. We'll have to see what trickles in from the field. It could be a combination of elements: strobe supplies, landing lights, brands of switches, date codes of switches and a general awareness of the problem. Give it some time. I think we'll hear more about this. We have three solid, documented cases of similar failures, plus two more anecdotal cases. I hope not for everyone's sake, but let's be diligent about looking for problems. Thanks, Vern > Vern, > > Don't you think that if it was an application problem that > we'd be hearing from people on a few orders of magnitude more > than we have? There must be several hundred people using > these switches in these circuits. No?? > > -Tom > ________________________________________________________________________________
From: "Mike Pienaar" <mjpienaar(at)shaw.ca>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
Hi All, Could somebody please explain in simple language what "high inrush currents" are. Thanks Mike ----- Original Message ----- From: "Vernon Little" <rv-9a-online(at)telus.net> Sent: Thursday, September 18, 2008 11:53 AM Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > Hi Jeff. This came up previously, and the answer is that they are all > supported properly. It appears that the underlying cause may be a > combination of high inrush currents and "economy" switches that start the > thermal runaway cycle: switch heating causes rivets to loosen; loose > rivets > cause more switch heating. > > With the exception of one switch, all of the problems have been in the > strobe and landing/taxi light circuits in multiple aircraft. > > I'm hoping for more results from the list members who are checking their > switches for damage or overheating using the finger test. > > Thanks, Vern > >> -----Original Message----- >> From: owner-aeroelectric-list-server(at)matronics.com >> [mailto:owner-aeroelectric-list-server(at)matronics.com] On >> Behalf Of Jeff Page >> Sent: September 18, 2008 11:08 AM >> To: aeroelectric-list(at)matronics.com >> Subject: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs >> >> >> >> >> Any chance that unsupported wires are vibrating in flight and >> helping >> to loosen the rivets, which then heat up from poor contact ? >> >> Jeff Page >> Dream Aircraft Tundra #10 >> >> > From: "Vernon Little" <rv-9a-online(at)telus.net> >> > The most recent information I have from the new case >> documented in the >> > previous message is that yes, indeed, the switch rivets are >> loose. It >> > looks like a common contributing factor. >> >> >> >> >> >> > > > ________________________________________________________________________________
From: "Dennis & Anne Glaeser" <glaesers(at)wideopenwest.com>
Subject: Re: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
> Hi All, > Could somebody please explain in simple language what "high inrush currents" are. > Thanks > Mike When resistive items are cold, they have less resistance. So when power is first applied, the current draw is high - hence the name. As things warm up, resistance grows and the current drops to it's steady state value. Dennis Glaeser ________________________________________________________________________________
From: "S. Ramirez" <simon(at)synchronousdesign.com>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 18, 2008
Mike, a high inrush current is caused by a device that has an initial low resistance. This resistance then increases as a function of time. I can think of two simple devices that will do this to a switch First is a capacitive load, or more accurately a capacitive-resistive load. With this type of load, you are charging up a capacitor. If the capacitor is not charged up initially, then the only thing limiting the current is the resistor. If the resistance is small, it will result in a "high inrush current." As the capacitor charges up, the current decreases toward zero. Second is a non-linear resistance such as an incandescent lamp. Such a lamp has a filament that is cold when it first passes current. When cold, the filament has low resistance and thus allows a "high inrush current." As the filament's temperature increases to produce light, its resistance increases, and thus the current decreases. There may be other simple examples and if so, anyone please feel free to chime in. I hope this helps. Mike, it just so happens that when a switch makes or breaks is the worst possible time for a high current or voltage to be occurring, as it takes its toll on the contacts due to arcing. Simon Copyright C 2008 -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mike Pienaar Sent: Thursday, September 18, 2008 9:56 PM Subject: Re: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs Hi All, Could somebody please explain in simple language what "high inrush currents" are. Thanks Mike ----- Original Message ----- From: "Vernon Little" <rv-9a-online(at)telus.net> Sent: Thursday, September 18, 2008 11:53 AM Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > Hi Jeff. This came up previously, and the answer is that they are all > supported properly. It appears that the underlying cause may be a > combination of high inrush currents and "economy" switches that start the > thermal runaway cycle: switch heating causes rivets to loosen; loose > rivets > cause more switch heating. > > With the exception of one switch, all of the problems have been in the > strobe and landing/taxi light circuits in multiple aircraft. > > I'm hoping for more results from the list members who are checking their > switches for damage or overheating using the finger test. > > Thanks, Vern > >> -----Original Message----- >> From: owner-aeroelectric-list-server(at)matronics.com >> [mailto:owner-aeroelectric-list-server(at)matronics.com] On >> Behalf Of Jeff Page >> Sent: September 18, 2008 11:08 AM >> To: aeroelectric-list(at)matronics.com >> Subject: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs >> >> >> >> >> Any chance that unsupported wires are vibrating in flight and >> helping >> to loosen the rivets, which then heat up from poor contact ? >> >> Jeff Page >> Dream Aircraft Tundra #10 >> >> > From: "Vernon Little" <rv-9a-online(at)telus.net> >> > The most recent information I have from the new case >> documented in the >> > previous message is that yes, indeed, the switch rivets are >> loose. It >> > looks like a common contributing factor. ________________________________________________________________________________
Date: Sep 18, 2008
From: Dale Rogers <dale.r(at)cox.net>
Subject: Re: re: Brad's reply on P-lead switch functionality
Robert L. Nuckolls, III wrote: > > > Received a reply from Brad on functionality of the p-lead switch > in Emag products: > > "Grounding the p-lead 1) sends a status signal to the processor > (telling it > to stop firing), and 2) disables the driver chips (so they can't fire)." Umm, that ~sounds~ good - but what does it mean? In the 30+ years that I've been working with computer hardware, I've never run across that expression for stopping the processor. In situations were a runaway process could result in damage, the normal method for halting a processor isn't via a status semaphore, but by halting the CPU clock pulse stream - either via grounding the output of the clock, or removing power from the clock crystal. With no clock pulses, the CPU cannot execute instructions, period. It's the only way to be completely certain that the CPU will in fact stop. Dale R. > ---------------------------------------- > > > > > >Jeff, although a good point to bring up, I highly doubt that such an > >important function would go to the microprocessor, except as a status > input. > >Surely it would go to a hard wired shut off circuit outside the micro > >to guarantee outside control without software being involved. If it > >didn't, it would be a major design error. However, all of these > >details are most likely proprietary data, and only Emagair would know. > > > >Simon > -------------------------------------- > >Subject: AeroElectric-List: Re: E-Mag P-Mag Safety info - Referenced > >msg from Mr. Cotner > > > > > >Any possibility that grounding the P-Lead would have no effect if the > >microcontroller was way too busy handling strangely timed interrupts > >due to the timing sensor bouncing around ? That would depend on > >whether the P-Lead is a standard input read by the microcontroller, or > >goes directly to some circuitry that shuts off the spark outputs. > >Anyone know how the circuirty is designed ? > > > >Jeff Page > >Dream Aircraft Tundra #10 > ________________________________________________________________________________
From: Joemotis(at)aol.com
Date: Sep 18, 2008
Subject: Re: Toggle Switches with Fast-On Tabs
Does anyone with these switches in question also have a laser thermometer to shoot their switch bank with? Might be interesting although not very scientific. Most assuredly would find a hot one though. Joe Motis Do not archive **************Looking for simple solutions to your real-life financial challenges? Check out WalletPop for the latest news and information, tips and calculators. (http://www.walletpop.com/?NCID=emlcntuswall00000001) ________________________________________________________________________________
Date: Sep 19, 2008
From: Harley <harley(at)AgelessWings.com>
Subject: Re: re: Brad's reply on P-lead switch functionality
Dale Rogers wrote: > > Robert L. Nuckolls, III wrote: >> >> >> Received a reply from Brad on functionality of the p-lead switch >> in Emag products: >> >> "Grounding the p-lead 1) sends a status signal to the processor >> (telling it >> to stop firing), and 2) disables the driver chips (so they can't fire)." > > Umm, that ~sounds~ good - but what does it mean? In the 30+ > years that I've been working with computer hardware, I've > never run across that expression for stopping the processor. > > In situations were a runaway process could result in damage, > the normal method for halting a processor isn't via a status > semaphore, but by halting the CPU clock pulse stream - > either via grounding the output of the clock, or removing > power from the clock crystal. With no clock pulses, the CPU > cannot execute instructions, period. It's the only way to be > completely certain that the CPU will in fact stop. > > Dale R. Morning, Dale... The way I read it, is that the P-lead "signal" tells the cpu to STOP FIRING (the spark plugs), not to stop. I assume that the processor continues running...the P-lead "signal" also disables the driver chips, which I assume are what actually direct the higher voltage to fire the spark plugs. These drivers are the devices that actually stop functioning. So, the processor keeps running, but is told to stop firing the driver chips, and in case it doesn't, the driver chips are also disabled as a back up, I would assume. Looking back on what I just wrote, a lot of assumptions, huh? Harley Dixon ________________________________________________________________________________
From: "David & Elaine Lamphere" <dalamphere(at)comcast.net>
Subject: Re: re: Brad's reply on P-lead switch functionality
Date: Sep 19, 2008
Why would you intepret that statement to mean "stop the processor" ?? The way I read that statement "status signal sent to the processor (telling it to stop firing)" meant the program that was running would no longer execute the "ignition fire" routine.. It could be done with a simple "if" statement, etc,... depends on the programming language used... Made sense to me. Dave L. ----- Original Message ----- From: "Dale Rogers" <dale.r(at)cox.net> Sent: Thursday, September 18, 2008 10:44 PM Subject: Re: AeroElectric-List: re: Brad's reply on P-lead switch functionality > > Robert L. Nuckolls, III wrote: >> >> >> Received a reply from Brad on functionality of the p-lead switch >> in Emag products: >> >> "Grounding the p-lead 1) sends a status signal to the processor (telling >> it >> to stop firing), and 2) disables the driver chips (so they can't fire)." > > Umm, that ~sounds~ good - but what does it mean? In the 30+ > years that I've been working with computer hardware, I've > never run across that expression for stopping the processor. > > In situations were a runaway process could result in damage, > the normal method for halting a processor isn't via a status > semaphore, but by halting the CPU clock pulse stream - > either via grounding the output of the clock, or removing > power from the clock crystal. With no clock pulses, the CPU > cannot execute instructions, period. It's the only way to be > completely certain that the CPU will in fact stop. > > Dale R. > ________________________________________________________________________________
Date: Sep 19, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Toggle Switches with Fast-On Tabs
> > >Vern, > >Don't you think that if it was an application problem that we'd be hearing >from people on a few orders of magnitude more than we have? There must be >several hundred people using these switches in these circuits. No?? More like thousands. The sum total of years those switches were sold first by AEC and then B&C is about 15. ------------------------------------ Is their a manufacturing date or any number on the switches that would let you identify a bad batch of switches? Sounds like some switches come with loose rivets and some don't have loose rivets. Is that correct? The manufacture should be able to tell you if loose rivets are acceptable. Loose rivets are not acceptable. If you refer to the sketch at: http://www.aeroelectric.com/Pictures/Switches/Toggle_Switch_with_Fast-On_Tabs.jpg The hollow rivets at (3) and (8) are what hold the switch internal parts together -AND- provide a conductive path from part to part. As soon as the rivet's retaining force goes down, resistance goes up, heating goes up, and the device starts down the path to failure. --------------------------------------- I understand that your switches were "properly" supported. Just wondering if the wire "support" needs to be more substantial than usual if there are large gauge wires involved, such as would be expected for landing light circuits? My thinking is that the larger the wire, the more momentum it has when vibrating due to it's mass. Secondly, maybe I've missed something here, but concerning the "loose" rivets. It is thought that the rivets are loose because of overheating, or vibration (with a heavy wire attached), or poor manufacturing process or what? Bevan, you may be on to something here . . . I'm embarrassed to have overlooked it up to now . . . Over the past week, I've received 5 corpses of dearly departed switches. All had loose rivets on the current carrying tabs. The OFF side tab was solidly retained by their rivets. Here's an exemplar photo set: These two pictures show the moving ON and OFF-side contacts. Noticeably free of signs of electrical stress. http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_01.jpg http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_02.jpg This picture shows the "saddle sores" that one would expect in a switch where the teeter-totter shaft was properly undersized . . . (Ref http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/Anatomy_of_a_Switch_Failure.html) to sit in the saddle. http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_03.jpg --------------- The spring-rate of the coil spring inside the toggle was checked against a new switch and found to be the same within measurement tolerances. It takes right at a pound of force to push the plastic actuator post flush with the end of the hollow toggle shaft . . . http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_06.jpg --------------- This switch has loose rivets at the ON-side tab (left) and the center tab. OFF-side rivet was tight. Note signs of heating induced corrosion on the left side rivet. http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_04.jpg http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_09.jpg ---------------- Here's a familiar picture . . . http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_08.JPG We've seen this on-side vs. off-side bending of the teeter- totter before. Notice the darker copper color on the right. This was the ON-side contact that was running warmer but the OFF-side was more severely deformed from flat. ---------------------- Here's a really cool picture . . . http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_05.jpg This switch was obviously powered at the center terminal. The teeter-totter was sufficiently distorted to cause teasing arc marks on BOTH the on and off extremes. I say "teasing" because this had to be going on for some time to make such strong marks before the failure progressed to the point where it was popping circuit protection. ------------------------------- This picture shows perfectly good On and Off-side contacts in addition to the bright areas in the bottom of the saddle pocket. The ON-side contact is on the right with barely detectable signs of elevated temperature operation. http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_10.jpg ----------------------------------- This picture is shows the teeter-totter as removed and before the lubrication was wiped off. http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_11.jpg ---------------------------------- This picture shows the loose rivet at the ON-side tab but the tab itself is not showing signs of strong heating. http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_12.jpg ----------------------------------- Here's the OFF-side tab. Tight rivet, bright clean brass. http://www.aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_14.jpg ----------------------------------- The common feature of all the carcasses I received was distortion of the teeter-totter from flat to a bowed condition of various degrees. The teeter-totter metal had lost temper and bent with heating and operational hammering being the predominant stresses. Stationary and moving contacts of all failed switches showed only slight if any visible effects of heating. All switches had loose rivets at the connection tabs. (note that my sketched cross-section has the center rivet (8) reversed. The head-formed-on-assembly is on the inside of the switch, not the outside). When dissecting a chain of failure events, one tries to deduce the first event . . . it's not unlike looking for the point of origin in a burned building. In this case, we're attempting to deduce the weakest (hence most likely to be overstressed) feature and then see if the damage patterns radiate out from that feature. In the case of the analysis published earlier this year, there were striking patterns laid down on the teeter-totter pivot that could easily be interpreted as a point of origin for chain of failures. However, Bevan's question about mechanical stresses to the tabs due to wire weight and bundling was an "eureka moment" of sorts. Consider the cross section sketch and photos of the riveted tabs and know that the weakest mechanical feature of these switches is the point where the hollow rivets are formed over to achieve retention forces that hold the parts together PLUS a gas-tight connection between the rivet and it's companion pieces and parts. While the failed switches were mostly concentrated in the ship's higher current systems, we've seen failures in the low current systems too (battery master). Nonetheless, Vern has experienced a rash of failures that spanned the full range of current carrying tasks. Consider the effects of a wire (heavier in the landing light and strobe systems) hanging off the back of the switch. Consider the effects of a wire bundle that is supported by the switch terminals with bundle-to-switch pigtails that are relatively short. There's a strong moment arm from the end of the tab that allows vibration of attached mass to put tension on the rolled over edges of the driven-head of the rivets. This makes more sense as a proximate root cause of the constellation of failures we've studied. Once gas-tightness of the rivet head is compromised, then corrosion goes up, resistance goes up, heating goes up, corrosion accelerates, etc. etc. I think I recall writing some words to the effect that pigtails that come off the backs of switches should have some substantial length before they drop into a wire bundle. The goal is two-fold: (1) service loop length to allow removal and replacement of the switch without disturbing other switches or the bundle and (2) a stress reliever that prevents mass of the wire bundle from adding to the vibrational stresses on the switch's tabs. I think I suggested a 2" service loop that offered free-slack in the leadwire between bundle and switch terminal. In the $high$ switches, the effects of mis-installation are reduced by the manner in which wire attach terminals are retained in the switch housing. See: http://www.aeroelectric.com/Pictures/Switches/Toggle_Switch_with_Mold-Captured_Terminals.jpg Vern, take a look at your installation for the purpose of assessing probability that vibration in the wire bundle mass is being conducted to the rivet joints due to a short-coupled installation of the attach wires. If this new hypothesis proves plausible, then it may well explain the rash of failures noted in a product with an exceedingly rich history in the marketplace. This has been nagging at me since this thread began. Lots of mud was thrown against the wall about AC vs. DC, failure to observe ratings, high inrush due to nature of the loads, etc. Yet we were still dealing with a legacy product manufactured in the millions and used with success in aircraft since the 60s. There had to be a common thread that tied all of what we observed together in a rational assemblage of simple-ideas. Current working hypothesis: Loss of gas-tight integrity at the rolled head of the rivets anchors a chain of failures that manifests itself with signs of heating, distortion of the teeter-totter, internal shorting of teeter-totter to the frame and loss of continuity through the switch. I think we may be getting closer . . . Bob . . . ________________________________________________________________________________
Date: Sep 19, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: re: Brad's reply on P-lead switch functionality
> >Robert L. Nuckolls, III wrote: >> >> >>Received a reply from Brad on functionality of the p-lead switch >>in Emag products: >> >>"Grounding the p-lead 1) sends a status signal to the processor (telling it >>to stop firing), and 2) disables the driver chips (so they can't fire)." > >Umm, that ~sounds~ good - but what does it mean? In the 30+ >years that I've been working with computer hardware, I've >never run across that expression for stopping the processor. > >In situations were a runaway process could result in damage, >the normal method for halting a processor isn't via a status >semaphore, but by halting the CPU clock pulse stream - >either via grounding the output of the clock, or removing >power from the clock crystal. With no clock pulses, the CPU >cannot execute instructions, period. It's the only way to be >completely certain that the CPU will in fact stop. Brad's description of the p-lead signal functionality may be interpreted as follows: First, it sets a discrete input to the processor that causes the software routines to stop triggering the coil for the purpose of generating a spark. The processor doesn't "halt in place" it's expected to recognize an operational command and to honor that command until it goes away. Second, the p-lead is tied to the 'drivers' between logic level (processor) and power level (spark coil) such that no communication between them is possible. I.e., even if the processor has wandered off into the weeds, the physical connection between logic and output is broken. I do this in all of my processor or logic based smart actuator designs. There's a "logic world" that runs at 5 volts in itty-bitty chunks (read fragile) of silicon and provide the "smart" side of the actuator's design. Then there's the power side . . . usually a brushless DC motor with ratings from 0.1 to several horsepower . . . it runs on 28VDC at lots of amps. To get "smarts" to communicate with "power" you need a combination of level shifters and drivers that translate from the 5 volt milliamps world to the 28 volt amps world. I always bring the operating power for these drivers or level shifters out to interface with the ship's flight management systems. Since these systems are already certified with level B or level A software, I let THEM do failure monitoring on my product while providing with a brick-wall-shutdown for causing my operation to cease. This feature relieves my software and hardware from both the rigors of high-risk software certification AND the need to do failure monitoring. I can push those tasks off onto hardware and software that is already taking on that responsibility for other systems . . . so adding my system to it is not burdensome. But it works only if you have this brick-wall-shutdown feature not unlike that which Emag has incorporated into their product. Bob . . . ________________________________________________________________________________
Date: Sep 19, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Vern's crimp tool performance . . .
Vern, I was able to run a resistance measurement on your newly installed terminals and got readings on the order of 200 micro-ohms . . . right in step with the values I get from a PIDG terminal installed with an AMP T-head tool. I was unable to measure the crimps on the terminals off the failed switch . . . not enough lead-length to get a grip on. But I did cross section the crimp and got the following photomicrograph . . . http://aeroelectric.com/Pictures/Misc/VL_Crimp_Tool_1.jpg The terminal from the failed switch exhibits no voids in the wire grip. Of course, you used this tool on other terminals NOT attached to switches and you've not seen a failure there so the results of my little look-see were predictable. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Vern's crimp tool performance . . .
Date: Sep 19, 2008
Thanks, Bob. I think you've safely eliminated bad crimps as a contributing factor. Much apprectiated. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Robert L. Nuckolls, III > Sent: September 19, 2008 9:12 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Vern's crimp tool performance . . . > > > > --> > > Vern, > > I was able to run a resistance measurement on your newly > installed terminals and got readings on the order of 200 > micro-ohms . . . right in step with the values I get from a > PIDG terminal installed with an AMP T-head tool. > > I was unable to measure the crimps on the terminals off the > failed switch . . . not enough lead-length to get a grip on. > But I did cross section the crimp and got the following > photomicrograph . . . > > http://aeroelectric.com/Pictures/Misc/VL_Crimp_Tool_1.jpg > > The terminal from the failed switch exhibits no voids in > the wire grip. Of course, you used this tool on other > terminals NOT attached to switches and you've not seen a > failure there so the results of my little look-see were predictable. > > > Bob . . . > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > > > > > > ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Toggle Switches with Fast-On Tabs
Date: Sep 19, 2008
Bob, thanks for your detailed response and analysis. I'll take some photos of the wiring next week to see if I have overlooked a potential source of vibration and unsupported wiring. I'll also see if I get photos from my friend's panel showing the same. It may be that vibration per se is not the issue, but in combination with suspect rivets and large currents, we have the recipe for problems. I do know that I've received new Carling switches with suspect rivets. One suggestion that I got was to solder the tabs to the rivets, but I am worried that may screw up the temper of the materials. Of note: we have at least one non-Carling switch failure as well. One thing that I didn't pay too much attention to was stress on the terminals from the wires. Perhaps the terminals are putting torque or bending preloads on the tabs that are stressing the tab/rivet joint. In fact, additional post-installation tie-wraps in the bundles tend to pull wires off of their natural alignment and cause these stresses. When I'm crawling under the panel with my camera, I will check the wire grooming. My bias on this (looking at my photos and my friend's) is that wire grooming is at most a secondary contributing factor. Given the wide variation in wiring techniques in the OBAM community, if this was the cause, we'd have serious trouble. Maybe I'll blame it on mud-dauber wasps, that's popular! V > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Robert L. Nuckolls, III > Sent: September 19, 2008 6:38 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Toggle Switches with Fast-On Tabs > > > > --> > > > > > > >Vern, > > > >Don't you think that if it was an application problem that we'd be > >hearing from people on a few orders of magnitude more than we have? > >There must be several hundred people using these switches in these > >circuits. No?? > > More like thousands. The sum total of years those switches > were sold > first by AEC and then B&C is about 15. > ------------------------------------ > > > Is their a manufacturing date or any number on the switches > that would let > you identify a bad batch of switches? Sounds like some > switches come with > loose rivets and some don't have loose rivets. Is that correct? > > The manufacture should be able to tell you if loose rivets > are acceptable. > > Loose rivets are not acceptable. If you refer to the sketch > at: > > http://www.aeroelectric.com/Pictures/Switches/Toggle_Switch_wi > th_Fast-On_Tabs.jpg > > The hollow rivets at (3) and (8) are what hold the switch internal > parts together -AND- provide a conductive path from part to part. > As soon as the rivet's retaining force goes down, resistance > goes up, heating goes up, and the device starts down the path > to failure. > --------------------------------------- > > > I understand that your switches were "properly" supported. > Just wondering > if the wire "support" needs to be more substantial than usual > if there are > large gauge wires involved, such as would be expected for > landing light > circuits? My thinking is that the larger the wire, the more > momentum it has > when vibrating due to it's mass. > > Secondly, maybe I've missed something here, but concerning the "loose" > rivets. It is thought that the rivets are loose because of > overheating, or > vibration (with a heavy wire attached), or poor manufacturing > process or > what? > > Bevan, you may be on to something here . . . I'm embarrassed > to have overlooked it up to now . . . > > Over the past week, I've received 5 corpses of dearly departed > switches. All had loose rivets on the current carrying tabs. The > OFF side tab was solidly retained by their rivets. Here's an > exemplar photo set: > > These two pictures show the moving ON and OFF-side contacts. > Noticeably free of signs of electrical stress. > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_01.jpg > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_02.jpg > > This picture shows the "saddle sores" that one would expect > in a switch where the teeter-totter shaft was properly > undersized . . . > > (Ref > http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failu > re/Anatomy_of_a_Switch_Failure.html) > > to sit in the saddle. > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_03.jpg > --------------- > > The spring-rate of the coil spring inside the toggle was checked > against a new switch and found to be the same within measurement > tolerances. It takes right at a pound of force to push the plastic > actuator post flush with the end of the hollow toggle shaft . . . > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_06.jpg > > --------------- > > This switch has loose rivets at the ON-side tab (left) and > the center tab. OFF-side rivet was tight. Note signs of heating > induced corrosion on the left side rivet. > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_04.jpg > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_09.jpg > > ---------------- > > Here's a familiar picture . . . > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_08.JPG > > We've seen this on-side vs. off-side bending of the teeter- > totter before. Notice the darker copper color on the right. This > was the ON-side contact that was running warmer but the OFF-side > was more severely deformed from flat. > > ---------------------- > > Here's a really cool picture . . . > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_05.jpg > > This switch was obviously powered at the center terminal. The > teeter-totter was sufficiently distorted to cause teasing arc > marks on BOTH the on and off extremes. I say "teasing" because > this had to be going on for some time to make such strong marks > before the failure progressed to the point where it was popping > circuit protection. > > ------------------------------- > > This picture shows perfectly good On and Off-side contacts > in addition to the bright areas in the bottom of the > saddle pocket. The ON-side contact is on the right with > barely detectable signs of elevated temperature operation. > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_10.jpg > > > ----------------------------------- > > This picture is shows the teeter-totter as removed and before > the lubrication was wiped off. > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_11.jpg > > > ---------------------------------- > > This picture shows the loose rivet at the ON-side tab > but the tab itself is not showing signs of strong > heating. > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_12.jpg > > ----------------------------------- > > Here's the OFF-side tab. Tight rivet, bright clean > brass. > > http://www.aeroelectric.com/Pictures/Switches/Carling_Failures > /BRA_14.jpg > > ----------------------------------- > > The common feature of all the carcasses I received was > distortion of the teeter-totter from flat to a bowed > condition of various degrees. The teeter-totter metal > had lost temper and bent with heating and operational > hammering being the predominant stresses. > > Stationary and moving contacts of all failed switches > showed only slight if any visible effects of heating. > > All switches had loose rivets at the connection tabs. > (note that my sketched cross-section has the center > rivet (8) reversed. The head-formed-on-assembly is on > the inside of the switch, not the outside). > > When dissecting a chain of failure events, one tries > to deduce the first event . . . it's not unlike looking > for the point of origin in a burned building. In this > case, we're attempting to deduce the weakest (hence > most likely to be overstressed) feature and then > see if the damage patterns radiate out from that > feature. > > In the case of the analysis published earlier this > year, there were striking patterns laid down on the > teeter-totter pivot that could easily be interpreted > as a point of origin for chain of failures. However, > Bevan's question about mechanical stresses to the > tabs due to wire weight and bundling was an "eureka > moment" of sorts. > > Consider the cross section sketch and photos of > the riveted tabs and know that the weakest mechanical > feature of these switches is the point where the hollow > rivets are formed over to achieve retention forces > that hold the parts together PLUS a gas-tight connection > between the rivet and it's companion pieces and parts. > > While the failed switches were mostly concentrated > in the ship's higher current systems, we've seen > failures in the low current systems too (battery > master). Nonetheless, Vern has experienced a rash > of failures that spanned the full range of current > carrying tasks. > > Consider the effects of a wire (heavier in the > landing light and strobe systems) hanging off the > back of the switch. Consider the effects of a wire > bundle that is supported by the switch terminals > with bundle-to-switch pigtails that are relatively > short. There's a strong moment arm from the end of > the tab that allows vibration of attached mass to > put tension on the rolled over edges of the > driven-head of the rivets. > > This makes more sense as a proximate root cause of > the constellation of failures we've studied. Once > gas-tightness of the rivet head is compromised, > then corrosion goes up, resistance goes up, heating > goes up, corrosion accelerates, etc. etc. > > I think I recall writing some words to the effect > that pigtails that come off the backs of switches > should have some substantial length before they > drop into a wire bundle. The goal is two-fold: > (1) service loop length to allow removal and > replacement of the switch without disturbing other > switches or the bundle and (2) a stress reliever > that prevents mass of the wire bundle from adding > to the vibrational stresses on the switch's tabs. > I think I suggested a 2" service loop that offered > free-slack in the leadwire between bundle and > switch terminal. > > In the $high$ switches, the effects of mis-installation > are reduced by the manner in which wire attach terminals > are retained in the switch housing. See: > > http://www.aeroelectric.com/Pictures/Switches/Toggle_Switch_wi > th_Mold-Captured_Terminals.jpg > > Vern, take a look at your installation for the purpose > of assessing probability that vibration in the > wire bundle mass is being conducted to the rivet > joints due to a short-coupled installation of the > attach wires. > > If this new hypothesis proves plausible, then it > may well explain the rash of failures noted in > a product with an exceedingly rich history in > the marketplace. This has been nagging at me since > this thread began. Lots of mud was thrown against > the wall about AC vs. DC, failure to observe ratings, > high inrush due to nature of the loads, etc. > > Yet we were still dealing with a legacy product > manufactured in the millions and used with > success in aircraft since the 60s. There > had to be a common thread that tied all of what > we observed together in a rational assemblage > of simple-ideas. > > Current working hypothesis: Loss of gas-tight > integrity at the rolled head of the rivets anchors > a chain of failures that manifests itself with > signs of heating, distortion of the teeter-totter, > internal shorting of teeter-totter to the frame and > loss of continuity through the switch. > > I think we may be getting closer . . . > > Bob . . . > > > > > > > > ________________________________________________________________________________
From: Speedy11(at)aol.com
Date: Sep 19, 2008
Subject: Re: E-Mag P-Mag Safety info
Bob, Thanks for acting as our expert go-between with EMagAir. I've been tempted to call them, but I'm sure they would prefer to avoid another phone call or email of possible. Your contact with them answered questions for all of us while simultaneously reducing the duplicative responses for Brad. Stan Sutterfield Call Emag and if push comes to shove, run a Magneto/Emag combination for awhile. Bottom line is that the sky is not falling. **************Looking for simple solutions to your real-life financial challenges? Check out WalletPop for the latest news and information, tips and calculators. (http://www.walletpop.com/?NCID=emlcntuswall00000001) ________________________________________________________________________________
From: "S. Ramirez" <simon(at)synchronousdesign.com>
Subject: re: Brad's reply on P-lead switch functionality
Date: Sep 19, 2008
-----Original Message----- >> >> >> Received a reply from Brad on functionality of the p-lead switch >> in Emag products: >> >> "Grounding the p-lead 1) sends a status signal to the processor >> (telling it >> to stop firing), and 2) disables the driver chips (so they can't fire)." > Umm, that ~sounds~ good - but what does it mean? In the 30+ > years that I've been working with computer hardware, I've > never run across that expression for stopping the processor. > In situations were a runaway process could result in damage, > the normal method for halting a processor isn't via a status > semaphore, but by halting the CPU clock pulse stream - > either via grounding the output of the clock, or removing > power from the clock crystal. With no clock pulses, the CPU > cannot execute instructions, period. It's the only way to be > completely certain that the CPU will in fact stop. > Dale R. Dale, By now you've seen Bob's reply about how the P-lead is a discrete input to the processor to cause the software routines to stop an output from triggering the actual spark drivers, AND the P-lead is also a hard-wired input to the spark drivers. Thus the processor isn't expected to halt in place; it is expected to recognize the input and honor it. If it doesn't honor it and is lost in the weeds, the P-lead will command the spark drivers to halt spark generation anyway. As Bob put insinuated, this relieves Emagair from the rigors or high-risk software certification and the need to do failure monitoring by pushing the tasks off onto hardware. This is good design practice, regardless. Now, I do agree with you that if something goes wrong big time and you want to kill the processor to avoid further harm, it is good to kill the clock, but one other thing must be done and that is to asynchronously reset all hardware. Asynchronously resetting hardware assures that all flip flops will reach a known state regardless of whether there is a clock or not, and all outputs should be a function of these states, either directly or through combinatorial circuitry. There are several ways to achieve a quiet clock, but grounding (crow-barring) a clock or any output, for that matter, is not good design practice, as it affects circuit reliability later on. Killing the clock is true only for today's synchronous CPUs. I was aware of two companies in the 1990s that were involved in designing asynchronous CPUs for the benefit that asynchronocity brings, but they went under as far as I know; however, some other company or government entity may have bought their technology and made product somewhere without my knowledge. Such product, of course, uses no clock. I cannot foresee asynchronous CPUs being with us in the near future, so I shouldn't even have brought them up! I just wanted to CMA. Simon ________________________________________________________________________________
Date: Sep 19, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: E-Mag P-Mag Safety update . . .
>Bob, >Thanks for acting as our expert go-between with EMagAir. I've been >tempted to call them, but I'm sure they would prefer to avoid another >phone call or email of possible. Your contact with them answered >questions for all of us while simultaneously reducing the duplicative >responses for Brad. >Stan Sutterfield > >Call Emag and if push comes to shove, run a Magneto/Emag combination >for awhile. Bottom line is that the sky is not falling. I've been having some private conversations with interested parties hoping to put a team effort together to evaluate Emag's proposed fix for wandering magnets . . . and assuage market-place concerns about these serious failures modes. It seems that my proposal is not in conformance with the business model of some invitees. In the mean time, know that if you are in possession of a device described in Emag's service bulletin, you're well advised to take them up on the offer of upgrade. I've got an alterative plan to explore for verification of design integrity. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 20, 2008
From: Michael Forhan <ohioip(at)yahoo.com>
Subject: Jabiru Alternator/Regulator OVM Problem
I am running a Jabiru 2200 with about 60 hours. I have the B&C "crowbar" overvoltage module ("OVM") installed and it has been fine until today. Today I flew for about half an hour. When I throttled back to about 2400 RPM for descent the 5A circuit breaker began tripping. No problems were noted at cruise RPM and idle/taxi RPM. There were no changes in the load on the electrical system--it's a basic VFR setup with only a COM radio and engine gauges on the DC bus. The analog panel voltmeter is reading about 14 VDC with the breaker in, but of course that would not provide any indication of transients that might be tripping the OVM. I'm suspecting the regulator--I previously posted here about problems with an unstable VDO tach reading with the tach input connected to an alternator lead. Perhaps the problems are related. Before I start digging into the electrical system, has anyone else seen a similar problem or have any suggestions? Thanks! ________________________________________________________________________________
Date: Sep 21, 2008
From: "Robert Feldtman" <bobf(at)feldtman.com>
Subject: Re: Jabiru Alternator/Regulator OVM Problem
I found the small 3A fuse in the voltage sample line to be loose, intermittently allowing for a break in the circuit, this too "low" a voltage, thus the VR would allow the voltage to rise intermittently which would of course pop the OV circuit breaker. The cheap 3 A fust holder was removed, and I put another 3 A in line fuse holder in place which stays snug. problem fixed bobf On Sat, Sep 20, 2008 at 10:35 PM, Michael Forhan wrote: > > I am running a Jabiru 2200 with about 60 hours. I have the B&C "crowbar" > overvoltage module ("OVM") installed and it has been fine until today. > > Today I flew for about half an hour. When I throttled back to about 2400 > RPM for descent the 5A circuit breaker began tripping. No problems were > noted at cruise RPM and idle/taxi RPM. > > There were no changes in the load on the electrical system--it's a basic > VFR setup with only a COM radio and engine gauges on the DC bus. > > The analog panel voltmeter is reading about 14 VDC with the breaker in, but > of course that would not provide any indication of transients that might be > tripping the OVM. > > I'm suspecting the regulator--I previously posted here about problems with > an unstable VDO tach reading with the tach input connected to an alternator > lead. Perhaps the problems are related. > > Before I start digging into the electrical system, has anyone else seen a > similar problem or have any suggestions? > > Thanks! > > ________________________________________________________________________________
Subject: Garmin 296 hard wire
From: "wypaul" <loadout(at)bresnan.net>
Date: Sep 21, 2008
I purchased an automotive charging cable that I plan to use to hard wire my 296 to my plane. When I opened the cigarette lighter end there was a small, square ceramic in series with the positive lead. What is the function of this component? I use a small power jack in place of the cigarette lighter so I guess it is not really hard wired and would like to get rid of the extra bulk. Paul Spackman -------- Paul Spackman Q-2 Jabiru 3300 Read this topic online here: http://forums.matronics.com/viewtopic.php?p 5364#205364 ________________________________________________________________________________
Date: Sep 21, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Garmin 296 hard wire
> >I purchased an automotive charging cable that I plan to use to hard wire >my 296 to my plane. When I opened the cigarette lighter end there was a >small, square ceramic in series with the positive lead. What is the >function of this component? I use a small power jack in place of the >cigarette lighter so I guess it is not really hard wired and would like to >get rid of the extra bulk. >Paul Spackman If it's a single, two-lead ceramic component, my best GUESS is a "Polyswitch". It's a sort of self-resetting circuit breaker. Here's a extensive description of these critters: http://en.wikipedia.org/wiki/Polyswitch For your purposes, an upstream fuse on the order of 2A or less would serve the same purpose. Having your accessory power jack fused at the bus is always a good thing. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 21, 2008
From: Paul McAllister <l_luv2_fly(at)yahoo.com>
Subject: S2-Servo
Hi All, I was wondering if anyone happened to know where the S2 Servo that Naviad use is sourced from. Trio seem to use a very similar servo in their product, perhaps it is the same unit, Anyhow, if anyone happens to know where these are sourced from I'd appreciate an heads up. Thanks, Paul ________________________________________________________________________________
Date: Sep 21, 2008
From: "Jeff Page" <jpx(at)Qenesis.com>
Subject: Z13/8 Aux Alternator Fuselink
There have been discussions here that the B&C SD-8 alternator can perhaps put out as much as 10A under some conditions. The wiring shown for it in Z13/8 is 14awg which matches the wire size charts for 10A. The Book indicates 4 awg sizes smaller for fuselinks, yet the fuselink shown for the SD-8 alternator at the main battery contactor is only 20awg. The same 14awg with 20awg fuselink combination is shown for the connection from the Endurance bus to the Alternate Feed relay. Should the fuselinks be 18 awg ? Thanks ! Jeff Page Dream Aircraft Tundra #10 ________________________________________________________________________________
From: "Bill" <docyukon(at)ptcnet.net>
Subject: Re: S2-Servo
Date: Sep 21, 2008
Me also, and or any servo that will work with the navaid head. Bill ----- Original Message ----- From: Paul McAllister To: aeroelectric-list(at)matronics.com Sent: Sunday, September 21, 2008 1:42 PM Subject: AeroElectric-List: S2-Servo Hi All, I was wondering if anyone happened to know where the S2 Servo that Naviad use is sourced from. Trio seem to use a very similar servo in their product, perhaps it is the same unit, Anyhow, if anyone happens to know where these are sourced from I'd appreciate an heads up. Thanks, Paul ------------------------------------------------------------------------- ----- Checked by AVG - http://www.avg.com 9/21/2008 10:10 AM ________________________________________________________________________________
Date: Sep 21, 2008
From: "Robert Feldtman" <bobf(at)feldtman.com>
Subject: Re: S2-Servo
check with trio - their's probably will. they have been very helpful bobf On Sun, Sep 21, 2008 at 5:57 PM, Bill wrote: > Me also, and or any servo that will work with the navaid head. > Bill > > ----- Original Message ----- > *From:* Paul McAllister > *To:* aeroelectric-list(at)matronics.com > *Sent:* Sunday, September 21, 2008 1:42 PM > *Subject:* AeroElectric-List: S2-Servo > > Hi All, > > I was wondering if anyone happened to know where the S2 Servo that Naviad > use is sourced from. Trio seem to use a very similar servo in their > product, perhaps it is the same unit, > > Anyhow, if anyone happens to know where these are sourced from I'd > appreciate an heads up. > > Thanks, Paul > > * > > href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List > href="http://forums.matronics.com">http://forums.matronics.com > href="http://www.matronics.com/contribution">http://www.matronics.com/c* > > ------------------------------ > - - Release Date: 9/21/2008 10:10 AM > > * > > * > > ________________________________________________________________________________
Date: Sep 21, 2008
From: Charlie England <ceengland(at)bellsouth.net>
Subject: Re: S2-Servo
I can verify that. I bought a used Navaid & then discovered that they were out of business. Trio says that they can modify their current servo to work with the navaid head. Trio bought servos from Navaid until they came up with their own 'smart' servo. Charlie Robert Feldtman wrote: > > check with trio - their's probably will. they have been very helpful > > bobf > > > On Sun, Sep 21, 2008 at 5:57 PM, Bill > wrote: > > Me also, and or any servo that will work with the navaid > head. Bill > > ----- Original Message ----- > *From:* Paul McAllister > *To:* aeroelectric-list(at)matronics.com > > *Sent:* Sunday, September 21, 2008 1:42 PM > *Subject:* AeroElectric-List: S2-Servo > > Hi All, > > I was wondering if anyone happened to know where the S2 Servo > that Naviad use is sourced from. Trio seem to use a very > similar servo in their product, perhaps it is the same unit, > > Anyhow, if anyone happens to know where these are sourced from > I'd appreciate an heads up. > > Thanks, Paul > ________________________________________________________________________________
Date: Sep 21, 2008
From: Jim Wickert <jimw_btg(at)earthlink.net>
Subject: S2 Swevo Navaid
I believe you find this is packaged by Navaid and that it is a Micro Stepper Motor with a Micro chopper to give the count control and positioning that is packaged by them. Much like most of the Trim and altitude hold supplier (they will use a stepper motor and a chopper circuit). The key is to design the control circuit, the reduction graring and the brake. A lot of work for one off. VOE!!! Jim Wickert Vision #159 ________________________________________________________________________________
Date: Sep 21, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Z13/8 Aux Alternator Fuselink
> >There have been discussions here that the B&C SD-8 alternator can >perhaps put out as much as 10A under some conditions. > >The wiring shown for it in Z13/8 is 14awg which matches the wire size >charts for 10A. Depending on the chart . . . 14AWG is good for 15A in a 10C rise design . . . see below . . . >The Book indicates 4 awg sizes smaller for fuselinks, yet the fuselink >shown for the SD-8 alternator at the main battery contactor is only >20awg. > >The same 14awg with 20awg fuselink combination is shown for the >connection from the Endurance bus to the Alternate Feed relay. > >Should the fuselinks be 18 awg ? No, current ratings for any given size of wire is dependent upon the TEMPERATURE RISE you're willing to tolerated along with VOLTAGE DROP you're willing to tolerate. The wire tables like those shown in http://aeroelectric.com/articles/Rev11/Ch8_R12.pdf are crafted for a 10C rise above ambient. In the case of using wire for fusible links, the fusible part is short . . . so it contributes little to overall voltage drop. We allow it to run a bit hotter to keep the wire size as small as practical (faster acting fuse for hard faults). In the cases you cited, 20AWG is at least 4 AWG steps smaller than 14, in fact it's 6 steps for an even faster fusing characteristic. Actually, you COULD use 22AWG for this fusible link if you wanted. See: http://aeroelectric.com/Pictures/Wire/22AWG_20A.pdf In this picture, we see a length of 22AWG wire in the foreground with a thermocouple attached. The wire has been carrying 20 amps for the last 30 minutes or so (temperature has stabilized). Note that the surface temperature of the wire is only 111C . . . we COULD run another 40C hotter without pushing this wire's insulation. 10A would drop the rise by about 1/2 down to about 85C. Even better yet. Fusible link fabrication is a special case that ignores (but does not abuse) the rules we use for sizing wire in bundles to carry power around the airplane. Bob . . . ________________________________________________________________________________
Date: Sep 22, 2008
From: "Jeff Page" <jpx(at)Qenesis.com>
Subject: Re: Z13/8 Aux Alternator Fuselink
> Depending on the chart . . . 14AWG is good for 15A in > a 10C rise design . . . see below . . . I would have expected all the charts to be the same. Measuring temperature rise versus current should be an easily repeatable experiment. I suppose the result landed midway between practical values, so some folks rounded up and others rounded down ? > In the case of using wire for fusible links, the > fusible part is short . . . so it contributes little > to overall voltage drop. We allow it to run a bit > hotter to keep the wire size as small as practical > (faster acting fuse for hard faults). In the cases > you cited, 20AWG is at least 4 AWG steps smaller than > 14, in fact it's 6 steps for an even faster fusing > characteristic. Actually, you COULD use 22AWG for > this fusible link if you wanted. See: The Connection suggests 4 awg smaller as a typical size for fuselinks. Z13/8 is using 6 awg smaller. I understand the tradeoff between a fuselink that blows quickly when needed versus temperature rise in normal use. So is 6 awg smaller a better rule of thumb ? Or is there a particular temperature rise that would be a good point to select instead ? Thanks ! Jeff Page Dream Aircraft Tundra #10 ________________________________________________________________________________
Subject: Brand New Apple iphone 3g 16gb,Nokia n96,Backbarry
From: "alexelectronics" <alexkrieger(at)rocketmail.com>
Date: Sep 22, 2008
Company Name - Alex Electronics Reg:No.00078717 Address: 21 OAK ROAD, HALE, ALTRINCHAM, CHESHIRE, WA15 9JA Incorporation Date: 10-04-1995 Contact#: +447035933744 e-mail alex.electronics(at)hotmail.com alexelectronics(at)technologist.com Alex Electronics Ltd is a specialized supplier of Mobile phones (GSM and CDMA),Video Games ,Apple Ipods , Iphone , HTC, Nokia / Sony Ericsson/Samsung/Motorola/Side Kicks.Laptops, computers, LCD, plasma T.v, Games and many more With high quality products, best service and good reputation, All products are brand new ( mobiles/unlocked ) factory sealed with original packets and complete accessory. Moreover, we also offer all kinds of international brand OEM/ODM service. Our services and terms are base on customers relationship and trust for effective and long term business relationship.Please feel free to contact us for more details. We ship and deliver to you within 2 Working days of purchase through FedEx / DHL / UPS courier services to deliver at your door post. Below is some of our products for order placement ----------------- LG ----------------- LG KE800 Special Edition @ 250usd LG KE970 Shine 3G @ 200usd LG KE770 Shine@ 180usd LG KE850 Prada @300usd ------------------ Motorola ------------------- Motorola RIZR Z8 @ 350usd Motorola RIZR Z6 @ 330usd Motorola RAZR V3XX Unlocked @ 200usd Motorola RAZR maxx V6 Ferrari Challenge @ 280usd Motorola RAZR Maxx @ 250usd Motorola Q9 @ 350usd Motorola KRZR K3 @ 300usd Motorola KRZR @ 240usd Motorola E6 @ 200usd -------------------- Nokia ---------------------- Nokia n95 8gb @350usd Nokia N93i@ 280usd Nokia n93 @ 250usd Nokia N92 @ 200usd Nokia N91 8GB@240usd Nokia N80 @240usd Nokia N76 @240usd Nokia N75 @200usd Nokia N73 @180usd Nokia N70 @150usd Nokia E90 Communicator @350usd Nokia E65 @ 250usd Nokia E61i @200usd Nokia 8801 @ 2200usd Nokia 8800 Sirocco @250usd Nokia 770 Internet @ 200usd ----------------------- iMate ----------------------- iMate Ultimate 5150 @280usd iMate SP Jam @250usd iMate PDAL @ 280usd iMate Jaq 4 @250usd iMate Jaq 3 @2280usd iMate JAQ @ 220usd iMate JAM @ 200usd ------------------------- Apple iPhone ----------------------- Apple iPhone 3G 16GB @300 Apple iPhone 4GB Unlocked @ 300usd Apple iPhone 8GB Unlocked @320usd ----------------------- BlackBerry ---------------------- BlackBerry 8320 CURVE (UNLOCKED) @ $250 Blackberry 8800 "indigo" (unlocked) @ 250usd Blackberry 8700g @ 220usd Blackberry 8100 Pearl Cingular (unlocked) @200usd ----------------------- ETEN ----------------------- ETEN X500 Glofiish @ 200usd ETEN M700 Glofiish 2 @240usd ETEN M600 @ 200usd ETEN G500 @ 150usd E-TEN X800 Glofiish @ 300usd ------------------------ Okwap Sanrio hello kitty i885 mobile @ 250usd Okwap i885 Sanrio Hello Kitty Cell @ 250 usd ------------------------- TomTom Go 910 GPS Car Navigation System @ 240usd TomTom Go 510 GPS @ 200usd ------------------------ OQO model 01+ Ultra PC @450usd OQO model 02 Ultra PC (pre-order) @430usd OQO model 02 Ultra PC (pre-order) @ 450usd -------------------------- Sony Ericsson ------------------------- Sony Ericsson W950i @ 260uad Sony Ericsson W880i Walkman Phone @ 250usd Sony Ericsson W850i @ 215usd Sony Ericsson W810i Walkman Phone @ 180usd Sony Ericsson W660i @ 200usd Sony Ericsson M600i @ 280usd Sony Ericsson K810i Cyber-shot Digital Camera Phone @ 280usd Sony Ericsson K800i @ 200usd Sony Ericcson P990i @ 350usd ---------------------------- Palm Treo ---------------------------- Palm Treo 750v (open box) @280usd Palm Treo 750 Unlocked Cingular @250usd Palm Treo 680 (Graphite) @ 200usd --------------------- Samsung -------------------- Samsung Z720 @ 180usd Samsung Ultra Edition 5.9 @ 300usd Samsung SGH-P310 @ 180usd Samsung SGH-i830 @ 200usd Samsung SGH-i718 @ 200uad Samsung SGH-i600 @180usd Samsung SGH-F700 @ 220usd Samsung SGH-B600 @ 350usd Samsung BlackJack SGH-i607 Unlocked @ 250usd Samsung BD-P1000 Blu-Ray Disc Player @ 300usd ------------------- HTC PHONES ---------------- Cingular 8125 @ 180usd Cingular 8525 @ 190usd HTC TyTn @ 300USD HTC 9100 Tmobile MDA (unlocked) @ 220usd HTC Advantage Pocket PC (Athena) @ 400usd HTC Kaiser @ 250usd HTC P3300 @ 240usd HTC P3350 @ 260usd HTC P3400 @ 220usd HTC P3600 (Trinity) @ 250usd HTC P6500 (HTC Sirius) 300usd HTC Dual @ $350 HTC S730 @ $390 HTC P6500@ 600 HTC Touch@ $300 HTC S710 @ $340 --------------------- Dj Equipments ---------------------- Pioneer AVIC-S1 @ $350usd Pioneer AVIC-Z1 Navigation AVICZ @ $600usd Pioneer AVIC-N3 Multimedia Navigation Receiver @ $550 Pioneer Avic-z1 Dvd Player Navigation System @ $500usd Pioneer AVIC-D1 / AVICD1 @ $400usd Pioneer AVIC-D2 DVD Navigation System @ $400USD GPS BLUETOOTH RECEIVER GNS 5843 GPS RDS TMC Bluetooth Receiver:::::::::::::::::::::::::230USD Holux GPS Bluetooth Receiver, Dongle & DELORME Maps 06::::::::::120USD Pharos GPS Receiver with Bluetooth Wireless Technology::::::::::100usd Navman GPS 4410 Bluetooth Receiver::::::::::::::::::::::::::::::220usd TOMTOM Navigator 5 Wireless Bluetooth GPS:::::::::::::::::::::::260usd Garmin 010-00378-00 GPS-10 Bluetooth Enabled GPS:::::::::::::::250usd ------------------------- APPLE LAPTOP ------------------------- Apple MacBook (MA700LL/A) Mac Notebook...................$500usd Apple MacBook Pro (MA611LL/A) Notebook...................$600usd Apple MacBook (MA254LL/A) Mac Notebook...................$450usd Apple iBook G3 (M7698LL/A) Mac Notebook..................$600usd Apple MacBook Pro (MA609LL/A) Notebook...................$550usd Apple MacBook Pro (MA600LLA) Notebook....................$500usd Apple MacBook Pro (MA610LL/A) Notebook...................$600usd Apple Macbook Pro (885909119400) Notebook................$600usd ------------------------ PANASONIC PLASMA TV ---------------------- Panasonic TH-37PHD8UK Plasma $400 Panasonic TH-42PWDlame 8UK Plasma $600 Panasonic TH-42PHD8UK Plasma $500 Panasonic TH-42PX50U Plasma $650 Panasonic TH-50PX50U Plasma $700 panasonic TH-65PHD8UK Plasma $900 ----------------------- SONY PLASMA TV ----------------------- SONY FWD-42PV1 Plasma Display $500 Sony PFM-42X1 Plasma Display $550 Sony FWD-50PX2 Plasma Display $700 ---------------------- SAMSUNG PLASMA TV ----------------------- SAMSUNG HPP3761 Plasma TV $610 Samsung PPM42M5S Plasma Display $505 Samsung SPP4251 Plasma TV $700 Samsung PPM42M5H Plasma Display $550 Samsung HPR4252 Plasma $680 Samsung HPR5052 Plasma $670 Samsung HPR5072 Plasma $780 ---------------------- HITACHI PLASMA TV ---------------------- Hitachi CMP4211u Plasma $850 Hitachi CMP4212u Plasma $350 Hitachi 42HDF52 Plasma HDTV $400 Hitachi 42HDT52 Plasma TV $440 Hitachi 55HDS52 Plasma HDTV $480 AOC ENVISION PLASMA TV AOC Envision A42W64 Plasma $400 MAXENT PLASMA TV Maxent MX-50X2 Plasma $300 GAME CONSOLE ----------- warranty ----------- 1 year international warranty. Free shipping for bulk purchase : 100% FedEx, DHL or UPS delivery guarantee :2 days maximum. OUR POLICY ************************ Our services and terms are base on customers relationship and trust for effective and long term business relationship. RETURN POLICY **************************** You may return the item within {30} days of delivery.Products with Manufacturer Warranty which exceed 40 days,could be returned directly to the manufacturer according instructions. For inquiry and order placement please contacts below. e-mail alex.electronics(at)hotmail.com alexelectronics(at)technologist.com Reg:No.00078717 Contact Person: Mr Alex Krieger We have many brand product not listed above.If you wish for any product not listed here please email us the product Brand Name and Model and we shall source it out. -------- alexelectronics Read this topic online here: http://forums.matronics.com/viewtopic.php?p 5511#205511 ________________________________________________________________________________
Subject: For Sale Laptops IBM,SONY VAIO P4 LAPTOP,TOSHIBA P4
LAPTOP:
From: "alexelectronics" <alexkrieger(at)rocketmail.com>
Date: Sep 22, 2008
We are Recognized Distributors of Various Consumer Electronics.Specialized in a wide Range of Products such as Mobile Phones,Video Games,Musical Instrument, Laptops,Digital Cameras, LCD Monitors,Plasma tv,Dj Equipments, Ipods, Xboxs and many more, Specification Details: Our products are brand new with complete accessories and it comes with 1 year international warranty . Below is our Price List for Order placement Laptops IBM Lenovo ThinkPad T60p (2623D8U) PC Notebook...............$600usd Lenovo ThinkPad(r) T43 (1875DMU) PC Notebook...............$500usd Lenovo Thinkpad T60 (1953D9U) PC Notebook................$550usd Lenovo 3000 N100 (0689A6U) PC Notebook...................$500usd Lenovo ThinkPad Z61m (945038U) PC Notebook...............$550usd Lenovo ThinkPad R60e (06573AU) PC Notebook...............$450usd Lenovo ThinkPad(r) T60p (8744C9U) PC Notebook..............$700usd APPLE LAPTOP Apple MacBook (MA700LL/A) Mac Notebook...................$500usd Apple MacBook Pro (MA611LL/A) Notebook...................$600usd Apple MacBook (MA254LL/A) Mac Notebook...................$450usd Apple iBook G3 (M7698LL/A) Mac Notebook..................$600usd Apple MacBook Pro (MA609LL/A) Notebook...................$550usd Apple MacBook Pro (MA600LLA) Notebook....................$500usd Apple MacBook Pro (MA610LL/A) Notebook...................$600usd Apple Macbook Pro (885909119400) Notebook................$600usd SONY VAIO P4 LAPTOP:- Sony VAIO(r) PCG-GRT100 (PCG-GRT10012) PC Notebook.........$400usd Sony VAIO(r) PCG-GRT100P (PCG-GRT100P3 PC Notebook....$500usd Sony VAIO(r) PCG-GRT100P (PCG-GRT100P56) PC Notebook.....$550usd Sony VAIO(r) PCG-GRT100P (PCG-GRT100P44) PC Notebook.....$480usd Sony VAIO(r) PCG-GRT100P (PCG-GRT100P17) PC Notebook......$300usd Sony VAIO(r) PCG-V505BCP (PCG-V505BCP11) PC Notebook.......$500usd Sony VAIO(r) PCG-GRT100K (PCG-GRT100K23) PC Notebook......$480usd HP LAPTOP:- Hewlett Packard Pavilion dv9260us PC Notebook......................$600usd Hewlett Packard Pavilion dv8140us (EP407UA) PCNotebook............$550usd Hewlett Packard Pavilion dv6265us PC Notebook......................$500usd Hewlett Packard Compaq Presario V6210US (RP203UA#ABA) PCNotebook.....$400usd Hewlett Packard Pavilion zd8230us PC Notebook..........$530usd Hewlett Packard Pavilion zd8205us PC Notebook...........$500usd Hewlett Packard Pavilion dv4170us (EC315UA) PC Notebook.....$400usd TOSHIBA P4 LAPTOP:- Toshiba Satellite(r) A75-S211 PCNotebook...................$580usd Toshiba Satellite(r) A75-S229 PC Notebook...................$600usd Toshiba Satellite A75-S213 PCNotebook.......................$650usd Toshiba Satelite 5205-S505 PC Notebook....................$620usd Toshiba Satellite P35-S605 PCNotebook......................$620usd Toshiba Satellite A25-S307 PCNotebook.......................$550usd ACER FERRARI P4 LAPTOP:- Acer Ferrari 5005WLMi PC Notebook.....................$600usd Acer Ferrari 4005WLMi PC Notebook......................$500usd Acer Ferrari 1004WTMi PC Notebook.......................$450usd Acer Ferrari 3400LMi PC Notebook...........................$400usd Acer Ferrari 1004WTMi PC Notebook........................$350usd ASSUS LAPTOP:- ASUS G2P (90NJVA823211141L100T) PC Notebook...............$550usd ASUS G1 (90NLAA1231211CAL400T) PC Notebook................$580usd ASUS W2Pb (90NHNA213153241L400T) PC Notebook..............$650usd ASUS A8Js (A8JS-4S024P) PC Notebook.......................$500usd ASUS VX1-5E004P (ASUNBVX15E003PDR) PC Notebook............$700usd ASUS W7J (90NHQA4235F3251L700T) PC Notebook...............$500usd ASUS G2P (G2P-7R009C) PC Notebook.........................$650usd Plasma TV Sony BRAVIA KDL46XBR2 46 in. HDTV LCD Television.....$900 Sony BRAVIA KDL-40XBR2 40 in. HDTV LCD Television.........$700 Sony BRAVIA KDL-46XBR3 46 in. HDTV LCD Television.....$900 Sony BRAVIA KDL-40V2500 40 in. HDTV LCD Television.......$700 Sony BRAVIA KDL-46V2500 46 in. HDTV LCD Television........$650 Sony BRAVIA KDL52XBR2 Television.........$1200 Sony BRAVIA KDL-52XBR3 Television.........$1000 Sony BRAVIA KDL-40XBR3 40 in. HDTV LCD Television.........$600 Sony BRAVIA KDL-V32XBR2 32 in. HDTV LCD Television.............$600 Sony KDF-E50A10 50 in. HDTV LCD Television.........$550 panasonic tv Panasonic TH58PX600U 58 in. HDTV Plasma Television..............$800 Panasonic TH58PX600U 57 in. HDTV Plasma Television..............$750 Pioneer PDP-4270HD 42 in. Plasma Television...............................$600 Panasonic TH-50PH9UK 50 in. Plasma Television...........................$700 Pioneer Elite PRO-FHD1 50 in. HDTV-Ready Plasma Television...$1500 Pioneer PDP-6070HD 60 in. Plasma Television.................................$1500 ------------------- NEC PLASMA TVS NEC 42XM3 Plasma TV...................$700 NEC 42XR3 Plasma TV..................$500 NEC 50XM4 Plasma TV..................$780 NEC 50XR4 Plasma TV .................$900 NEC 61XM3 Plasma TV .................$560 NEC 61XR3 Plasma TV .................$500 NEC 84VP4 Plasma TV .................$690 --------------------- Hitachi CMP4211u Plasma .............$850 Hitachi CMP4212u Plasma .............$350 Hitachi 42HDF52 Plasma HDTV..........$400 Hitachi 42HDT52 Plasma TV ...........$440 Hitachi 55HDS52 Plasma HDTV .........$480 Hitachi 55HDT52 Plasma TV ...........$650 Hitachi CMP-55HDM71 Plasma....... ..$420 Dj Equipments Pioneer Cdj Mixer Pioneer DJM-800 Mixer......$500 Pioneer DJM-1000 Mixer....$1000 Pioneer DJM-600 mixer.....$500 Pioneer DJM-600K mixer....$500 Pioneer DJM-500 mixer.....$350 Pioneer DJM-300 mixer....$150 Pioneer DJM-3000 mixer...$400 Pioneer DJM-707 mixer....$300 Turntable Pioneer CDJ-1000 MK3....$500 Pioneer CDJ-1000MK2.....$450 Pioneer CDJ-200 Pro CD Player ...............$150 Pioneer DVJ-X1 DJ Video Player........... $1000 Pioneer CDJ-800MK2 Professional CD/MP3 Turntable......... $350 Pioneer DVJ-1000 Professional DVD Turntable ............$1000 Technics SL-1210M5G Pro Turntable............... $350 Technics SL-1200MK2...............$240 Technics SL-DZ 1200.................$320 Technics SL-1210M5G Pro Turntable.. .$300 Technics SL-1210MK5 Pro Turntable ...$250 Technics SH-MZ1200 4 Channel DJ Mixer.........$250 Denon DN-D4500 Pro DJ Dual CD/MP3 Player...$400 Denon DN-D9000.....................$400 Denon DN-D6000.....................$500 Denon DN S3500 (CD player)....$250 Denon DN S5000 (CD player)....$300 Denon DN X1500s (Mixer).........$250 Denon DN-HD2500 ..................$350 Numark CDX Direct-Drive CD Turntable......$400 Numark TTX Direct-Drive Turntable............$300 Numark X2 Pro Hybrid Turntable And CD / MP3 Player.....$300 Numark DVD01 Dual DVD Player.........$250 Numark 5000FX 12" 5-Channel Tabletop Mixer ....$300 Numark DXM09 Digital DJ Mixer...$200 Numark AVM02 Audio/Video Mixer with Effects ......$400 Numark CM200USB 5-Channel 19" Rackmount DJ Mixer .......$250 Samsung NP-Q1U/001 - Q1 ULTRA UMPC-CMXP A110 800MHZ SYST1GB 80GB 7 ..$400 Samsung Q1B UMPC 1GHZ 40GB HD 512MB WLAN Bluetooth WIN XP Tablet ..........$250 Sony Ultra Mobile PCs (UMPC) VAIO UX Series VGN-UX390N Micro ........$420 OQO Model 02 - C7-M 1.5 GHz ULV - UMPC - RAM 1 GB - HDD 60 GB .....$400 ASUS R2H-BH059T-3 (90NGVA11M18A5611400T) Tablet PC..................$350 Sony Ultra Mobile PCs (UMPC) VAIO UX Series VGN-UX280P Micro ..........$400 UBiQUiO 711 /1.2GHz /1GB /40GB /Vista Tablet UMPC .......$5000 UMPC C7M/1.6 1GB 80GB WXPP................................$520 Sony VAIO UX Series VGN-UX280P VGNUX280P Micro Computer Ultra .....$400 ----------- warranty ----------- 1year international warranty. 100% delivery guarantee OUR POLICY ************************ Our services and terms are base on customers relationship and trust for effective and long term business relationship. RETURN POLICY **************************** You may return the item within {30} days of delivery.Products with Manufacturer Warranty which exceed 40 days,could be returned directly to the manufacturer according instructions. For inquiry and order placement please contacts below. e-mail alex.electronics(at)hotmail.com alexelectronics(at)technologist.com Reg:No.00078717 Contact Person: Mr Alex Krieger If you wish for any product not listed here please email us the product Brand Name and Model and i will source it from our warehouse. -------- alexelectronics Read this topic online here: http://forums.matronics.com/viewtopic.php?p 5512#205512 ________________________________________________________________________________
Date: Sep 22, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Z13/8 Aux Alternator Fuselink
> >> Depending on the chart . . . 14AWG is good for 15A in >> a 10C rise design . . . see below . . . > >I would have expected all the charts to be the same. Measuring >temperature rise versus current should be an easily repeatable >experiment. I suppose the result landed midway between practical >values, so some folks rounded up and others rounded down ? All charts ARE the same . . . i.e. based on some temperature rise driven by design goals. In other words, all 10C charts will be the same, 20C charts will agree, etc. If you're interested in viewing the full constellation of all charts, take a peek at the wire sizing exercises described in http://www.aeroelectric.com/Reference_Docs/FAA/AC43.13-1B_Ch11_Electrical.pdf >> In the case of using wire for fusible links, the >> fusible part is short . . . so it contributes little >> to overall voltage drop. We allow it to run a bit >> hotter to keep the wire size as small as practical >> (faster acting fuse for hard faults). In the cases >> you cited, 20AWG is at least 4 AWG steps smaller than >> 14, in fact it's 6 steps for an even faster fusing >> characteristic. Actually, you COULD use 22AWG for >> this fusible link if you wanted. See: > >The Connection suggests 4 awg smaller as a typical size for fuselinks. > Z13/8 is using 6 awg smaller. I understand the tradeoff between a >fuselink that blows quickly when needed versus temperature rise in >normal use. So is 6 awg smaller a better rule of thumb ? Or is there >a particular temperature rise that would be a good point to select >instead ? Your thumb is different than my thumb. Not trying to be obtuse here. I'm just pointing out the fact that there's a huge range of combinations that (1) do not offer excessive voltage drop - depending on your quantification of "excessive" and (2) do not put the wire's insulation at risk due to maximum anticipated continuous current, ambient temperature, and relative insulation from ambient due to bundling. I believe the major idea here is that it's probably not worth your productive $time$ to worry about it much. If you're wanting to acquire a more academic understanding, then the task before you is significant. You can start with AC43-13 and I can offer some other references. I made my recommendations knowing that the combination suggested was well inside the edges of the voltage-drop/temperature-rise envelope. Bob . . . ________________________________________________________________________________
From: "S. Ramirez" <simon(at)synchronousdesign.com>
Subject: Brand New Apple iphone 3g 16gb,Nokia n96,Backbarry
Date: Sep 22, 2008
Please, Bob, shut this stuff down. I get enough crap from other sources already. Simon Copyright 2008 -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of alexelectronics Sent: Monday, September 22, 2008 12:10 PM Subject: AeroElectric-List: Brand New Apple iphone 3g 16gb,Nokia n96,Backbarry Company Name - Alex Electronics Reg:No.00078717 Address: 21 OAK ROAD, HALE, ALTRINCHAM, CHESHIRE, WA15 9JA Incorporation Date: 10-04-1995 Contact#: +447035933744 e-mail alex.electronics(at)hotmail.com alexelectronics(at)technologist.com Alex Electronics Ltd is a specialized supplier of Mobile phones (GSM and CDMA),Video Games ,Apple Ipods , Iphone , HTC, Nokia / Sony Ericsson/Samsung/Motorola/Side Kicks.Laptops, computers, LCD, plasma T.v, Games and many more With high quality products, best service and good reputation, All products are brand new ( mobiles/unlocked ) factory sealed with original packets and complete accessory. Moreover, we also offer all kinds of international brand OEM/ODM service. Our services and terms are base on customers relationship and trust for effective and long term business relationship.Please feel free to contact us for more details. We ship and deliver to you within 2 Working days of purchase through FedEx / DHL / UPS courier services to deliver at your door post. Below is some of our products for order placement ----------------- LG ----------------- LG KE800 Special Edition @ 250usd LG KE970 Shine 3G @ 200usd LG KE770 Shine@ 180usd LG KE850 Prada @300usd ------------------ Motorola ------------------- Motorola RIZR Z8 @ 350usd Motorola RIZR Z6 @ 330usd Motorola RAZR V3XX Unlocked @ 200usd Motorola RAZR maxx V6 Ferrari Challenge @ 280usd Motorola RAZR Maxx @ 250usd Motorola Q9 @ 350usd Motorola KRZR K3 @ 300usd Motorola KRZR @ 240usd Motorola E6 @ 200usd -------------------- Nokia ---------------------- Nokia n95 8gb @350usd Nokia N93i@ 280usd Nokia n93 @ 250usd Nokia N92 @ 200usd Nokia N91 8GB@240usd Nokia N80 @240usd Nokia N76 @240usd Nokia N75 @200usd Nokia N73 @180usd Nokia N70 @150usd Nokia E90 Communicator @350usd Nokia E65 @ 250usd Nokia E61i @200usd Nokia 8801 @ 2200usd Nokia 8800 Sirocco @250usd Nokia 770 Internet @ 200usd ----------------------- iMate ----------------------- iMate Ultimate 5150 @280usd iMate SP Jam @250usd iMate PDAL @ 280usd iMate Jaq 4 @250usd iMate Jaq 3 @2280usd iMate JAQ @ 220usd iMate JAM @ 200usd ------------------------- Apple iPhone ----------------------- Apple iPhone 3G 16GB @300 Apple iPhone 4GB Unlocked @ 300usd Apple iPhone 8GB Unlocked @320usd ----------------------- BlackBerry ---------------------- BlackBerry 8320 CURVE (UNLOCKED) @ $250 Blackberry 8800 "indigo" (unlocked) @ 250usd Blackberry 8700g @ 220usd Blackberry 8100 Pearl Cingular (unlocked) @200usd ----------------------- ETEN ----------------------- ETEN X500 Glofiish @ 200usd ETEN M700 Glofiish 2 @240usd ETEN M600 @ 200usd ETEN G500 @ 150usd E-TEN X800 Glofiish @ 300usd ------------------------ Okwap Sanrio hello kitty i885 mobile @ 250usd Okwap i885 Sanrio Hello Kitty Cell @ 250 usd ------------------------- TomTom Go 910 GPS Car Navigation System @ 240usd TomTom Go 510 GPS @ 200usd ------------------------ OQO model 01+ Ultra PC @450usd OQO model 02 Ultra PC (pre-order) @430usd OQO model 02 Ultra PC (pre-order) @ 450usd -------------------------- Sony Ericsson ------------------------- Sony Ericsson W950i @ 260uad Sony Ericsson W880i Walkman Phone @ 250usd Sony Ericsson W850i @ 215usd Sony Ericsson W810i Walkman Phone @ 180usd Sony Ericsson W660i @ 200usd Sony Ericsson M600i @ 280usd Sony Ericsson K810i Cyber-shot Digital Camera Phone @ 280usd Sony Ericsson K800i @ 200usd Sony Ericcson P990i @ 350usd ---------------------------- Palm Treo ---------------------------- Palm Treo 750v (open box) @280usd Palm Treo 750 Unlocked Cingular @250usd Palm Treo 680 (Graphite) @ 200usd --------------------- Samsung -------------------- Samsung Z720 @ 180usd Samsung Ultra Edition 5.9 @ 300usd Samsung SGH-P310 @ 180usd Samsung SGH-i830 @ 200usd Samsung SGH-i718 @ 200uad Samsung SGH-i600 @180usd Samsung SGH-F700 @ 220usd Samsung SGH-B600 @ 350usd Samsung BlackJack SGH-i607 Unlocked @ 250usd Samsung BD-P1000 Blu-Ray Disc Player @ 300usd ------------------- HTC PHONES ---------------- Cingular 8125 @ 180usd Cingular 8525 @ 190usd HTC TyTn @ 300USD HTC 9100 Tmobile MDA (unlocked) @ 220usd HTC Advantage Pocket PC (Athena) @ 400usd HTC Kaiser @ 250usd HTC P3300 @ 240usd HTC P3350 @ 260usd HTC P3400 @ 220usd HTC P3600 (Trinity) @ 250usd HTC P6500 (HTC Sirius) 300usd HTC Dual @ $350 HTC S730 @ $390 HTC P6500@ 600 HTC Touch@ $300 HTC S710 @ $340 --------------------- Dj Equipments ---------------------- Pioneer AVIC-S1 @ $350usd Pioneer AVIC-Z1 Navigation AVICZ @ $600usd Pioneer AVIC-N3 Multimedia Navigation Receiver @ $550 Pioneer Avic-z1 Dvd Player Navigation System @ $500usd Pioneer AVIC-D1 / AVICD1 @ $400usd Pioneer AVIC-D2 DVD Navigation System @ $400USD GPS BLUETOOTH RECEIVER GNS 5843 GPS RDS TMC Bluetooth Receiver:::::::::::::::::::::::::230USD Holux GPS Bluetooth Receiver, Dongle & DELORME Maps 06::::::::::120USD Pharos GPS Receiver with Bluetooth Wireless Technology::::::::::100usd Navman GPS 4410 Bluetooth Receiver::::::::::::::::::::::::::::::220usd TOMTOM Navigator 5 Wireless Bluetooth GPS:::::::::::::::::::::::260usd Garmin 010-00378-00 GPS-10 Bluetooth Enabled GPS:::::::::::::::250usd ------------------------- APPLE LAPTOP ------------------------- Apple MacBook (MA700LL/A) Mac Notebook...................$500usd Apple MacBook Pro (MA611LL/A) Notebook...................$600usd Apple MacBook (MA254LL/A) Mac Notebook...................$450usd Apple iBook G3 (M7698LL/A) Mac Notebook..................$600usd Apple MacBook Pro (MA609LL/A) Notebook...................$550usd Apple MacBook Pro (MA600LLA) Notebook....................$500usd Apple MacBook Pro (MA610LL/A) Notebook...................$600usd Apple Macbook Pro (885909119400) Notebook................$600usd ------------------------ PANASONIC PLASMA TV ---------------------- Panasonic TH-37PHD8UK Plasma $400 Panasonic TH-42PWDlame 8UK Plasma $600 Panasonic TH-42PHD8UK Plasma $500 Panasonic TH-42PX50U Plasma $650 Panasonic TH-50PX50U Plasma $700 panasonic TH-65PHD8UK Plasma $900 ----------------------- SONY PLASMA TV ----------------------- SONY FWD-42PV1 Plasma Display $500 Sony PFM-42X1 Plasma Display $550 Sony FWD-50PX2 Plasma Display $700 ---------------------- SAMSUNG PLASMA TV ----------------------- SAMSUNG HPP3761 Plasma TV $610 Samsung PPM42M5S Plasma Display $505 Samsung SPP4251 Plasma TV $700 Samsung PPM42M5H Plasma Display $550 Samsung HPR4252 Plasma $680 Samsung HPR5052 Plasma $670 Samsung HPR5072 Plasma $780 ---------------------- HITACHI PLASMA TV ---------------------- Hitachi CMP4211u Plasma $850 Hitachi CMP4212u Plasma $350 Hitachi 42HDF52 Plasma HDTV $400 Hitachi 42HDT52 Plasma TV $440 Hitachi 55HDS52 Plasma HDTV $480 AOC ENVISION PLASMA TV AOC Envision A42W64 Plasma $400 MAXENT PLASMA TV Maxent MX-50X2 Plasma $300 GAME CONSOLE ----------- warranty ----------- 1 year international warranty. Free shipping for bulk purchase : 100% FedEx, DHL or UPS delivery guarantee :2 days maximum. OUR POLICY ************************ Our services and terms are base on customers relationship and trust for effective and long term business relationship. RETURN POLICY **************************** You may return the item within {30} days of delivery.Products with Manufacturer Warranty which exceed 40 days,could be returned directly to the manufacturer according instructions. For inquiry and order placement please contacts below. e-mail alex.electronics(at)hotmail.com alexelectronics(at)technologist.com Reg:No.00078717 Contact Person: Mr Alex Krieger We have many brand product not listed above.If you wish for any product not listed here please email us the product Brand Name and Model and we shall source it out. -------- alexelectronics Read this topic online here: http://forums.matronics.com/viewtopic.php?p 5511#205511 ________________________________________________________________________________
Date: Sep 22, 2008
From: "Richard Girard" <jindoguy(at)gmail.com>
Subject: Re: Brand New Apple iphone 3g 16gb,Nokia n96,Backbarry
Simon, I'm pretty sure Bob has no control over this. The person to contact is Matt Dralle, he can block this garbage. Rick On Mon, Sep 22, 2008 at 11:55 AM, S. Ramirez w rote: > simon(at)synchronousdesign.com> > > Please, Bob, shut this stuff down. I get enough crap from other sources > already. > > Simon > Copyright (c) 2008 > > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of > alexelectronics > Sent: Monday, September 22, 2008 12:10 PM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Brand New Apple iphone 3g 16gb,Nokia > n96,Backbarry > > > > Company Name - Alex Electronics > Reg:No.00078717 > Address: 21 OAK ROAD, HALE, ALTRINCHAM, > CHESHIRE, WA15 9JA > Incorporation Date: 10-04-1995 > Contact#: +447035933744 > > e-mail > alex.electronics(at)hotmail.com > alexelectronics(at)technologist.com > > Alex Electronics Ltd is a specialized supplier of Mobile phones (GSM and > CDMA),Video Games ,Apple Ipods , Iphone , HTC, Nokia / Sony > Ericsson/Samsung/Motorola/Side Kicks.Laptops, computers, LCD, plasma T.v, > Games and many more With high quality products, best service and good > reputation, All products are brand new ( mobiles/unlocked ) factory seal ed > with original packets and complete accessory. > > Moreover, we also offer all kinds of international brand OEM/ODM service. > Our services and terms are base on customers relationship and trust for > effective and long term business relationship.Please feel free to > contact us for more details. > > We ship and deliver to you within 2 Working days of purchase through > FedEx / DHL / UPS courier services to deliver at your door post. > Below is some of our products for order placement > ----------------- > LG > ----------------- > LG KE800 Special Edition @ 250usd > LG KE970 Shine 3G @ 200usd > LG KE770 Shine@ 180usd > LG KE850 Prada @300usd > ------------------ > Motorola > ------------------- > Motorola RIZR Z8 @ 350usd > Motorola RIZR Z6 @ 330usd > Motorola RAZR V3XX Unlocked @ 200usd > Motorola RAZR maxx V6 Ferrari Challenge @ 280usd > Motorola RAZR Maxx @ 250usd > Motorola Q9 @ 350usd > Motorola KRZR K3 @ 300usd > Motorola KRZR @ 240usd > Motorola E6 @ 200usd > -------------------- > Nokia > ---------------------- > Nokia n95 8gb @350usd > Nokia N93i@ 280usd > Nokia n93 @ 250usd > Nokia N92 @ 200usd > Nokia N91 8GB@240usd > Nokia N80 @240usd > Nokia N76 @240usd > Nokia N75 @200usd > Nokia N73 @180usd > Nokia N70 @150usd > Nokia E90 Communicator @350usd > Nokia E65 @ 250usd > Nokia E61i @200usd > Nokia 8801 @ 2200usd > Nokia 8800 Sirocco @250usd > Nokia 770 Internet @ 200usd > ----------------------- > iMate > ----------------------- > iMate Ultimate 5150 @280usd > iMate SP Jam @250usd > iMate PDAL @ 280usd > iMate Jaq 4 @250usd > iMate Jaq 3 @2280usd > iMate JAQ @ 220usd > iMate JAM @ 200usd > ------------------------- > Apple iPhone > ----------------------- > Apple iPhone 3G 16GB @300 > Apple iPhone 4GB Unlocked @ 300usd > Apple iPhone 8GB Unlocked @320usd > ----------------------- > BlackBerry > ---------------------- > BlackBerry 8320 CURVE (UNLOCKED) @ $250 > Blackberry 8800 "indigo" (unlocked) @ 250usd > 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> Sony Ericsson K800i @ 200usd > Sony Ericcson P990i @ 350usd > ---------------------------- > Palm Treo > ---------------------------- > Palm Treo 750v (open box) @280usd > Palm Treo 750 Unlocked Cingular @250usd > Palm Treo 680 (Graphite) @ 200usd > --------------------- > Samsung > -------------------- > Samsung Z720 @ 180usd > Samsung Ultra Edition 5.9 @ 300usd > Samsung SGH-P310 @ 180usd > Samsung SGH-i830 @ 200usd > Samsung SGH-i718 @ 200uad > Samsung SGH-i600 @180usd > Samsung SGH-F700 @ 220usd > Samsung SGH-B600 @ 350usd > Samsung BlackJack SGH-i607 Unlocked @ 250usd > Samsung BD-P1000 Blu-Ray Disc Player @ 300usd > ------------------- > HTC PHONES > ---------------- > Cingular 8125 @ 180usd > Cingular 8525 @ 190usd > HTC TyTn @ 300USD > HTC 9100 Tmobile MDA (unlocked) @ 220usd > HTC Advantage Pocket PC (Athena) @ 400usd > HTC Kaiser @ 250usd > HTC P3300 @ 240usd > HTC P3350 @ 260usd > HTC P3400 @ 220usd > HTC P3600 (Trinity) @ 250usd > HTC P6500 (HTC Sirius) 300usd > HTC Dual @ $350 > HTC S730 @ $390 > HTC P6500@ 600 > HTC Touch@ $300 > HTC S710 @ $340 > --------------------- > Dj Equipments > ---------------------- > Pioneer AVIC-S1 @ $350usd > Pioneer AVIC-Z1 Navigation AVICZ @ $600usd > Pioneer AVIC-N3 Multimedia Navigation Receiver @ $550 > Pioneer Avic-z1 Dvd Player Navigation System @ $500usd > Pioneer AVIC-D1 / AVICD1 @ $400usd > Pioneer AVIC-D2 DVD Navigation System @ $400USD > GPS BLUETOOTH RECEIVER > GNS 5843 GPS RDS TMC Bluetooth Receiver:::::::::::::::::::::::::230USD > Holux GPS Bluetooth Receiver, Dongle & DELORME Maps 06::::::::::120USD > Pharos GPS Receiver with Bluetooth Wireless Technology::::::::::100usd > Navman GPS 4410 Bluetooth Receiver::::::::::::::::::::::::::::::220usd > TOMTOM Navigator 5 Wireless Bluetooth GPS:::::::::::::::::::::::260usd > Garmin 010-00378-00 GPS-10 Bluetooth=C2(R) Enabled GPS:::::::::::::::250u sd > ------------------------- > APPLE LAPTOP > ------------------------- > Apple MacBook (MA700LL/A) Mac Notebook...................$500usd > Apple MacBook Pro (MA611LL/A) Notebook...................$600usd > Apple MacBook (MA254LL/A) Mac Notebook...................$450usd > Apple iBook G3 (M7698LL/A) Mac Notebook..................$600usd > Apple MacBook Pro (MA609LL/A) Notebook...................$550usd > Apple MacBook Pro (MA600LLA) Notebook....................$500usd > Apple MacBook Pro (MA610LL/A) Notebook...................$600usd > Apple Macbook Pro (885909119400) Notebook................$600usd > ------------------------ > PANASONIC PLASMA TV > ---------------------- > Panasonic TH-37PHD8UK Plasma $400 > Panasonic TH-42PWDlame 8UK Plasma $600 > Panasonic TH-42PHD8UK Plasma $500 > Panasonic TH-42PX50U Plasma $650 > Panasonic TH-50PX50U Plasma $700 > panasonic TH-65PHD8UK Plasma $900 > ----------------------- > SONY PLASMA TV > ----------------------- > SONY FWD-42PV1 Plasma Display $500 > Sony PFM-42X1 Plasma Display $550 > Sony FWD-50PX2 Plasma Display $700 > ---------------------- > SAMSUNG PLASMA TV > ----------------------- > SAMSUNG HPP3761 Plasma TV $610 > Samsung PPM42M5S Plasma Display $505 > Samsung SPP4251 Plasma TV $700 > Samsung PPM42M5H Plasma Display $550 > Samsung HPR4252 Plasma $680 > Samsung HPR5052 Plasma $670 > Samsung HPR5072 Plasma $780 > ---------------------- > HITACHI PLASMA TV > ---------------------- > Hitachi CMP4211u Plasma $850 > Hitachi CMP4212u Plasma $350 > Hitachi 42HDF52 Plasma HDTV $400 > Hitachi 42HDT52 Plasma TV $440 > Hitachi 55HDS52 Plasma HDTV $480 > AOC ENVISION PLASMA TV > AOC Envision A42W64 Plasma $400 > MAXENT PLASMA TV > Maxent MX-50X2 Plasma $300 > GAME CONSOLE > ----------- > warranty > ----------- > > 1 year international warranty. Free shipping for bulk purchase : 100% > FedEx, > DHL or UPS > > delivery guarantee :2 days maximum. > OUR POLICY > ************************ > Our services and terms are base on customers relationship and trust for > effective and long term business relationship. > RETURN POLICY > **************************** > You may return the item within {30} days of > delivery.Products with Manufacturer Warranty which > exceed 40 days,could be returned directly to the > manufacturer according instructions. > > For inquiry and order placement please contacts below. > > e-mail > alex.electronics(at)hotmail.com > alexelectronics(at)technologist.com > Reg:No.00078717 > Contact Person: Mr Alex Krieger > We have many brand product not listed above.If you wish for any product n ot > listed here > > please email us the product Brand Name and Model and we shall source it > out. > > -------- > alexelectronics > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p 5511#205511 > > =========== =========== =========== =========== > > ________________________________________________________________________________
Date: Sep 22, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Kitplanes article on an Elegant LED driver
Here's the data package on the filtered Buck Puck prototype. http://aeroelectric.com/Pictures/Lighting/Buck-Puck/ I was hoping I could get into the lab and look at DO-160 conducted . . . it's not in the stars this week. Shoot me an address to mail it to. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 23, 2008
From: rveighta <rveighta(at)earthlink.net>
Subject: Radio Problem
Bob, I have an Apollo SL-30 radio in my RV-8 which has a rather unique problem; on the ground, even with the engine running at high RPM, the radio transmits and receives flawlessly. In the air it's a different story. As soon as I take off, a loud background noise begins which makes receiving transmissions nearly impossible. Usually, sometime during the flight, this noise goes away and the reception is crystal clear. The background noise doesn't seem to affect transmissions I have a belly mounted Comant bent whip antenna. Coax connections are tight. Any idea of what the problem might be? Thanks, Walt Shipley ________________________________________________________________________________
Date: Sep 23, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Radio Problem
> >Bob, I have an Apollo SL-30 radio in my RV-8 which has a rather unique >problem; on the ground, even with the engine running at high RPM, the >radio transmits and receives flawlessly. In the air it's a different >story. As soon as I take off, a loud background noise begins which makes >receiving transmissions nearly impossible. Usually, sometime during the >flight, this noise goes away and the reception is crystal clear. The >background noise doesn't seem to affect transmissions > >I have a belly mounted Comant bent whip antenna. Coax connections are >tight. Any idea of what the problem might be? Do you have a hand-held transceiver you can connect to this antenna? It would be useful to know if the noise in coming in through the antenna or elsewhere. Does the noise go up and down with the radio's volume control? I presume you've explored potential antagonist devices in the airplane. Can you do a test flight with fuses/ breakers pulled for everything except engine and radio? Have you shut the alternator off to see if the noise goes away? Bob . . . ________________________________________________________________________________
Date: Sep 23, 2008
From: "Sam Hoskins" <sam.hoskins(at)gmail.com>
Subject: Source for welding cable?
I'm looking for a place to get some good 4AWG welding cable. (Small amounts- of course). I see McMaster-Carr has some, but I would prefer to get both black and red. Does anyone have any sources? I see some on Ebay also. Sam Hoskins Murphysboro, IL www.samhoskins.blogspot.com ________________________________________________________________________________
Date: Sep 23, 2008
Subject: Re: Radio Problem
From: "Matt Prather" <mprather(at)spro.net>
Is there a squelch on the monitored frequency? I haven't messed with an SL-30 enough to know, but I could imagine that the monitored frequency my pick up noise and drown out the primary frequency. Total conjecture on my part. Discard as necessary.. :) Regards, Matt- > > >> >> >>Bob, I have an Apollo SL-30 radio in my RV-8 which has a rather unique >>problem; on the ground, even with the engine running at high RPM, the >>radio transmits and receives flawlessly. In the air it's a different >>story. As soon as I take off, a loud background noise begins which makes >>receiving transmissions nearly impossible. Usually, sometime during the >>flight, this noise goes away and the reception is crystal clear. The >>background noise doesn't seem to affect transmissions >> >>I have a belly mounted Comant bent whip antenna. Coax connections are >>tight. Any idea of what the problem might be? > > Do you have a hand-held transceiver you can connect to > this antenna? It would be useful to know if the noise > in coming in through the antenna or elsewhere. Does > the noise go up and down with the radio's volume > control? > > I presume you've explored potential antagonist devices > in the airplane. Can you do a test flight with fuses/ > breakers pulled for everything except engine and radio? > > Have you shut the alternator off to see if the noise > goes away? > > Bob . . . > > ________________________________________________________________________________
Date: Sep 23, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Source for welding cable?
>I'm looking for a place to get some good 4AWG welding cable. (Small >amounts- of course). I see McMaster-Carr has some, but I would prefer to >get both black and red. Does anyone have any sources? I see some on Ebay >also. If not seen it in colors in my local suppliers inventory. The stuff I get here in Wichita is from a local welding supply store that supplies my CO2 for the environmental chamber. See: http://aeroelectric.com/Pictures/Wire/4AWG_Welding_Cable_1.jpg This stuff is designed primarily for rough service . . . lay out on gravel roads and be run over by dump-trucks. Local pricing for cut lengths is about $1.25/foot Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 23, 2008
From: "John McMahon" <blackoaks(at)gmail.com>
Subject: Re: Source for welding cable?
Hi Sam, I got mine from Wiremasters. Sedveral of us have used them, Deb was very helpful and the price for all their wire was the best I found. Deb Sullivan Account Executive *WireMasters, Inc.** *Phone: 800-635-5342 Fax: 615-791-6182 Email: dsullivan@ wiremasters.net Web site: http://www.wiremasters.net/ -- John McMahon Lancair Super ES, S/N 170, N9637M (Reserved) ________________________________________________________________________________
Date: Sep 23, 2008
From: "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net>
Subject: Source for welding cable?
Like anything else, there must be good and bad quality cable available out there. What would be the difference to look for? Sam I would recommend the VU-TRON cable. It has fine strands and is very flexible. Your application may or may not need the flexibility. It is also very durable. I was only able to find it in orange, but will use shrink sleeving to identify. It is a little more expensive but for me, worth the extra cost. My $.10 worth (inflation, you know) Roger ________________________________________________________________________________
Date: Sep 23, 2008
From: Jim Streit <wooody04(at)bellsouth.net>
Subject: Re: Source for welding cable?
Sam, B&C has it in both red & black and will cut whatever length you need Jim Streit 90073 Sam Hoskins wrote: > I'm looking for a place to get some good 4AWG welding cable. (Small > amounts- of course). I see McMaster-Carr has some, but I would prefer > to get both black and red. Does anyone have any sources? I see some > on Ebay also. > > Sam Hoskins > Murphysboro, IL > www.samhoskins.blogspot.com <http://www.samhoskins.blogspot.com> > > * > > > * > ------------------------------------------------------------------------ > > > Checked by AVG - http://www.avg.com > > ________________________________________________________________________________
From: "Bill" <docyukon(at)ptcnet.net>
Subject: current draw
Date: Sep 23, 2008
Can anyone tell me the expected current draw on a facet solid state fuel pump? ( 12v - 2.5/4.5 psi ) Also on rac servos. Thanks Bill S. ________________________________________________________________________________
From: "Bill Schlatterer" <billschlatterer(at)sbcglobal.net>
Subject: current draw
Date: Sep 23, 2008
<< Standard 12 V models require only 1 amp at max. delivery. >> From ACS Bill S 7a finishing _____ From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bill Sent: Tuesday, September 23, 2008 5:45 PM Subject: AeroElectric-List: current draw Can anyone tell me the expected current draw on a facet solid state fuel pump? ( 12v - 2.5/4.5 psi ) Also on rac servos. Thanks Bill S. ________________________________________________________________________________
Date: Sep 24, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: current draw
>Can anyone tell me the expected current draw on a facet solid state fuel >pump? ( 12v - 2.5/4.5 psi ) Also on rac servos. Thanks Bill S. The Ray Allen servos draw about 500 mA fully loaded. Most folks systems use 100 mA or so. Bob . . . ________________________________________________________________________________
From: "Ron Raby" <ronr(at)advanceddesign.com>
Subject: Re: Source for welding cable?
Date: Sep 24, 2008
I have a surplus roll of # 2 welding cable aprox 120 feet left. Back in 2000 I paid 90 cents per foot. I also have the lugs 2.50 ea and the right crimper to put them on. I will make the cable with the lugs installed for the cost of the material. I also can put on a piece of red heat shrink if you want. Regards Ron Raby www.advanceddesign.com ----- Original Message ----- From: John McMahon To: aeroelectric-list(at)matronics.com Sent: Tuesday, September 23, 2008 1:48 PM Subject: Re: AeroElectric-List: Source for welding cable? Hi Sam, I got mine from Wiremasters. Sedveral of us have used them, Deb was very helpful and the price for all their wire was the best I found. Deb Sullivan Account Executive WireMasters, Inc. Phone: 800-635-5342 Fax: 615-791-6182 Email: dsullivan@ wiremasters.net Web site: http://www.wiremasters.net/ -- John McMahon Lancair Super ES, S/N 170, N9637M (Reserved) ________________________________________________________________________________
Date: Sep 24, 2008
From: "Jeff Page" <jpx(at)Qenesis.com>
Subject: Re: Z13/8 Aux Alternator Fuselink
> I believe the major idea here is that it's probably not worth your > productive $time$ to worry about it much. If you're wanting > to acquire a more academic understanding, then the task before > you is significant. You can start with AC43-13 and I can offer > some other references. I made my recommendations knowing that > the combination suggested was well inside the edges of the > voltage-drop/temperature-rise envelope. I guess I am looking for some basic approaches so i can choose the size of a fuselink. The wire charts easily allow me to select a wire size for currents based on voltage drop and temperature rise. Is there a chart for fuselinks ? AC43-13 doesn't seem to even mention the word. The AeroElectric Connection says to use 4 agw smaller for fuselinks, but this discourse indicates that is incorrect. Continuing on in the theme, what about protection for the wire that activates the battery contactor ? The diode will fail open, but what about a short internal to the contactor due to, say, mechanical failure ? There would be an unfused 4awg wire feeding huge currents through the switched wire to ground. Although an unlikely possiblilty, it would be ugly if it happened. What about a fuselink on it ? What size ? Thanks, Jeff Page Dream Aircraft Tundra #10 ________________________________________________________________________________
Date: Sep 24, 2008
From: Christopher Stone <rv8iator(at)earthlink.net>
Subject: Re: Source for welding cable?
Sam... Check Waytek http://order.waytekwire.com/CGI-BIN/LANSAWEB?WEBEVENT+L0F99F83E3041F200097A061+M37+ENG Chris Stone RV-8 Newberg, OR -----Original Message----- >From: Sam Hoskins <sam.hoskins(at)gmail.com> >Sent: Sep 23, 2008 1:09 PM >To: Aerolectric List >Subject: AeroElectric-List: Source for welding cable? > >I'm looking for a place to get some good 4AWG welding cable. (Small amounts- >of course). I see McMaster-Carr has some, but I would prefer to get both >black and red. Does anyone have any sources? I see some on Ebay also. > >Sam Hoskins >Murphysboro, IL >www.samhoskins.blogspot.com ________________________________________________________________________________
Date: Sep 24, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Z13/8 Aux Alternator Fuselink
> >> I believe the major idea here is that it's probably not worth your >> productive $time$ to worry about it much. If you're wanting >> to acquire a more academic understanding, then the task before >> you is significant. You can start with AC43-13 and I can offer >> some other references. I made my recommendations knowing that >> the combination suggested was well inside the edges of the >> voltage-drop/temperature-rise envelope. > >I guess I am looking for some basic approaches so i can choose the >size of a fuselink. The wire charts easily allow me to select a wire >size for currents based on voltage drop and temperature rise. Is >there a chart for fuselinks ? AC43-13 doesn't seem to even mention >the word. The AeroElectric Connection says to use 4 agw smaller for >fuselinks, but this discourse indicates that is incorrect. And it shouldn't. You need to review the writings I've posted on fusible links. I've cautioned that they are not replacements for fuses or circuit breakers. They are circuit protection with timing constants on the same order as the ANL current limiters and similar devices used in the automotive world. I do not recommend their use in any locations and/or sizes not illustrated in the Z-figures. You seldom see them incorporated into the Z-figures and there's a reason for that . . . >Continuing on in the theme, what about protection for the wire that >activates the battery contactor ? The diode will fail open, but what >about a short internal to the contactor due to, say, mechanical >failure ? There would be an unfused 4awg wire feeding huge currents >through the switched wire to ground. Although an unlikely >possiblilty, it would be ugly if it happened. What about a fuselink >on it ? What size ? The Z-figures are direct descendants of system architectures that go back 70 years or more. They've been crafted to illustrate architecture and protection philosophies that have been filtered through the production history of hundreds of thousands of airplanes. The fact that no "protection" is shown on any given wire is not accidental. I've never seen or heard of a coil suppression device failing in service. They are VERY lightly stressed as-installed. I.e., not worthy of additional concern for protection against failure. Adding circuit protection where none is shown/needed/recommended only increases parts count and drives system reliability down. Bob . . . ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 24, 2008
Update on my findings. One question that I had was if vibration could be working the rivets loose on the Carling switches. Given that I believe the rivets to be suspect to begin with-- even new switches have loose rivets-- vibration may be a trigger for a cascade of overheating problems. I took a photo of my switches from under the panel, seen here: http://www.vx-aviation.com/rv-9a/photos/Electrical/IMG_0988_1.JPG. This photo shows the black sheathed wiring bundled which brings the airframe circuits to the panel, and the 2-3 inch pigtails to the switches. Based on my inspection, there may be a vibration coupling into the pigtails from the main bundle. Even though the bundle is secured every 8 inches or so, I was able to move it by hand in the vertical (pitch) dimension. Given the uncertainties here, I will not add more tie-downs to this bundle yet. I want to see if the switch replacement has done the trick. This may take a year or so to complete the experiment. If it solves the problem, we will know that the superior construction of the switches is a fix. If it does not, I will add tie downs to the bundle and re-run the experiment. The problem with doing both right now, is that we'll never know what the root cause was. I'm willing to sacrifice a few switches in the greater search for knowledge. At least this area is easy to get at! Vern ________________________________________________________________________________
From: "Ron Raby" <ronr(at)advanceddesign.com>
Subject: Re: Source for welding cable?
Date: Sep 24, 2008
I also have some extraflex 4awg tin coated fine stranded copper wire. The marking on the wire say's awm I A/B 105C FT1 LL59358. not sure what that means. seems better than welding cable. I paid 1.88 a foot. I have both black and green. I will sell it for a buck a foot. Regards Ron Raby ----- Original Message ----- From: Ron Raby To: aeroelectric-list(at)matronics.com Sent: Wednesday, September 24, 2008 9:35 AM Subject: Re: AeroElectric-List: Source for welding cable? I have a surplus roll of # 2 welding cable aprox 120 feet left. Back in 2000 I paid 90 cents per foot. I also have the lugs 2.50 ea and the right crimper to put them on. I will make the cable with the lugs installed for the cost of the material. I also can put on a piece of red heat shrink if you want. Regards Ron Raby www.advanceddesign.com ----- Original Message ----- From: John McMahon To: aeroelectric-list(at)matronics.com Sent: Tuesday, September 23, 2008 1:48 PM Subject: Re: AeroElectric-List: Source for welding cable? Hi Sam, I got mine from Wiremasters. Sedveral of us have used them, Deb was very helpful and the price for all their wire was the best I found. Deb Sullivan Account Executive WireMasters, Inc. Phone: 800-635-5342 Fax: 615-791-6182 Email: dsullivan@ wiremasters.net Web site: http://www.wiremasters.net/ -- John McMahon Lancair Super ES, S/N 170, N9637M (Reserved) href="http://www.matronics.com/Navigator?AeroElectric-List">http://www. matronics.com/Navigator?AeroElectric-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________________________________________________________
Subject: Re: Source for welding cable?
From: "rampil" <ira.rampil(at)gmail.com>
Date: Sep 24, 2008
for the few feet you probably need, it doesn't make sense to mail order it. any local welding supply will have appropriate cable. Welding cable by definition is fine stranded 100% copper. Buy a touch long since despite the fine stranding, it still has a significant bend radius -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p 5988#205988 ________________________________________________________________________________
From: "B Tomm" <fvalarm(at)rapidnet.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 24, 2008
Vern, I agree with the experiment. Be sure to add a couple switches and tools to the A/C repair kit. Probably a good thing to have on all our airplanes especially when away from home base. Bevan -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vernon Little Sent: Wednesday, September 24, 2008 9:35 AM Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs --> Update on my findings. One question that I had was if vibration could be working the rivets loose on the Carling switches. Given that I believe the rivets to be suspect to begin with-- even new switches have loose rivets-- vibration may be a trigger for a cascade of overheating problems. I took a photo of my switches from under the panel, seen here: http://www.vx-aviation.com/rv-9a/photos/Electrical/IMG_0988_1.JPG. This photo shows the black sheathed wiring bundled which brings the airframe circuits to the panel, and the 2-3 inch pigtails to the switches. Based on my inspection, there may be a vibration coupling into the pigtails from the main bundle. Even though the bundle is secured every 8 inches or so, I was able to move it by hand in the vertical (pitch) dimension. Given the uncertainties here, I will not add more tie-downs to this bundle yet. I want to see if the switch replacement has done the trick. This may take a year or so to complete the experiment. If it solves the problem, we will know that the superior construction of the switches is a fix. If it does not, I will add tie downs to the bundle and re-run the experiment. The problem with doing both right now, is that we'll never know what the root cause was. I'm willing to sacrifice a few switches in the greater search for knowledge. At least this area is easy to get at! Vern ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 24, 2008
Good idea. I'll keep the list posted on any developments. Vern > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of B Tomm > Sent: September 24, 2008 12:57 PM > To: aeroelectric-list(at)matronics.com > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > > > > > Vern, > > I agree with the experiment. Be sure to add a couple > switches and tools to the A/C repair kit. Probably a good > thing to have on all our airplanes especially when away from > home base. > > Bevan > > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Vernon Little > Sent: Wednesday, September 24, 2008 9:35 AM > To: aeroelectric-list(at)matronics.com > Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > --> > > Update on my findings. > > One question that I had was if vibration could be working the > rivets loose on the Carling switches. Given that I believe > the rivets to be suspect to begin with-- even new switches > have loose rivets-- vibration may be a trigger for a cascade > of overheating problems. > > I took a photo of my switches from under the panel, seen > here: > http://www.vx-aviation.com/rv-9a/photos/Electrical/IMG_0988_1.JPG. > > This photo shows the black sheathed wiring bundled which > brings the airframe circuits to the panel, and the 2-3 inch > pigtails to the switches. > > Based on my inspection, there may be a vibration coupling > into the pigtails from the main bundle. Even though the > bundle is secured every 8 inches or so, I was able to move it > by hand in the vertical (pitch) dimension. > > Given the uncertainties here, I will not add more tie-downs > to this bundle yet. I want to see if the switch replacement > has done the trick. This may take a year or so to complete > the experiment. If it solves the problem, we will know that > the superior construction of the switches is a fix. If it > does not, I will add tie downs to the bundle and re-run the > experiment. > > The problem with doing both right now, is that we'll never > know what the root cause was. I'm willing to sacrifice a few > switches in the greater search for knowledge. At least this > area is easy to get at! > > Vern > > > > > > > > > > > > > ________________________________________________________________________________
Date: Sep 24, 2008
From: Dale Rogers <dale.r(at)cox.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Vernon Little wrote: > Update on my findings. > > One question that I had was if vibration could be working the rivets loose > on the Carling switches. Given that I believe the rivets to be suspect to > begin with-- even new switches have loose rivets-- vibration may be a > trigger for a cascade of overheating problems. > Vern, If you have loose rivets on a new switch, the manufacturer has a QA problem. A tab that is not held in intimate contact the inner component with sufficient force to resist movement by finger pressure has already begun to fail. If I got switches like that from two or more production lots, that manufacturer would be off my supplier list. Dale R. Mesa, AZ COZY MkIV #0497 ________________________________________________________________________________
Date: Sep 25, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Toggle Switches with Fast-On Tabs
> >Vernon Little wrote: >>Update on my findings. >> >>One question that I had was if vibration could be working the rivets loose >>on the Carling switches. Given that I believe the rivets to be suspect to >>begin with-- even new switches have loose rivets-- vibration may be a >>trigger for a cascade of overheating problems. >> > >Vern, > > If you have loose rivets on a new switch, the manufacturer >has a QA problem. A tab that is not held in intimate contact >the inner component with sufficient force to resist >movement by finger pressure has already begun to fail. > > If I got switches like that from two or more production >lots, that manufacturer would be off my supplier list. Upon further reflection on the switch failure experiences of members of this List and examination of several corpses I'll suggest there is good reason to look very closely at the installation of these devices . . . in particular, providing sufficient service-slack on individual leads so that forces from a vibrating wire bundle cannot be transferred to the riveted fast-on tabs. The first failure we looked at . . . http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/Anatomy_of_a_Switch_Failure.html led us to believe that the point-of-origin for the cascade of effects was at the pivot saddle for the moveable contact bar . . . Subsequent postmortems showed no signs of internal heating source at the pivot saddle or contacts. These pictures are typical of carcass condition for all subsequent teardowns . . . http://aeroelectric.com/Pictures/Switches/Carling_Failures/ If one evaluates the construction of this product for a sense of mechanical weak-spots, the attachment of the tabs with hollow rivets has to be high on the list of concerns. Poor design? Not if used within established limits. All failures subsequent to the first showed significant effects of heating outside the switch in the form of discolored tabs, discolored insulation grips, loose rivets. There WAS enough effect of heating to take the temper out of the teeter-totter . . . http://aeroelectric.com/Pictures/Switches/Carling_Failures/BRA_08.JPG but no indication that the source of that heat was the pivot saddle or electrical-contacts. In every case, things DID get hot outside the switch. In one case, probability of poor connection within a heat-damaged PIDG terminal was discounted . . . http://aeroelectric.com/Pictures/Misc/VL_Crimp_Tool_1.jpg This suggests a modification of hypothesis for root cause. If vibration forces on the tabs compromises the gas-tight integrity of the joints at (3), (7) or (8) of http://aeroelectric.com/Pictures/Switches/Toggle_Switch_with_Fast-On_Tabs.jpg then the products of corrosion begin followed by an increase of resistance, followed by increased heating, followed by more corrosion . . . We can make this go faster yet by continuing to shake the fast-on tab with the same forces that precipitated the initial failure. Obviously, the higher the service-current for the switch, the faster things run down hill. So it's easy to understand why continuous duty, moderate current loads would produce the highest population of failures. But we've heard that a battery master . . . probably the lightest loaded switch in the airplane has also suffered a failure. I've received a number of e-mails from folks suggesting that "things are going to !@#$@#$ in a hand-basket now that Carling is assembling in Mexico". One could jump on that band-wagon IF there was a significant number of failures spread over a broad spectrum of users. Keep in mind that the OBAM aircraft community uses perhaps 0.0001% of all switches assembled with this process. Of all such switches in service, the OBAM aircraft community offers some of the highest levels of vibration and stresses that are byproducts of that vibration. Further, we've seen rashes of failures on the same aircraft over a spread of manufacturing date codes. I'll suggest there's good reason to fully explore extra- ordinary stresses on the rolled-rivet joints that result from conditions of installation. Bob . . . ________________________________________________________________________________
From: "Vernon Little" <rv-9a-online(at)telus.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 25, 2008
Hi Bob, see my commments: > ...Further, we've seen rashes of failures on > the same aircraft over a spread of manufacturing date codes. I've had 3, possibly 4 switch failures in my RV-9A. Another RV-9A had 2 similar failures. All except one were Carling switches > > I'll suggest there's good reason to fully explore extra- > ordinary stresses on the rolled-rivet joints that result > from conditions of installation. > > Bob . . . I am reasonably convinced that the combination of vibration, terminal rivet construction and high current loading is causing these failures. I will continue my experiment with a straight switch substitution to see if the Micro Switch brand has higher vibration tolerance. I will report any failures or successes in the next 100 hours of operation. Even if the new switches are successful, after 100 hours I will secure the wiring harness more positively to minimize vibration. The combination of (potentially) better switches and proper wire grooming will hopefully give me long term reliability. I hope others have learned from the problems I've had and are looking at their own installations for potential problems. Good Luck to everybody. Thanks, Vern ________________________________________________________________________________
Date: Sep 25, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Toggle Switches with Fast-On Tabs
> > >Hi Bob, see my commments: > > > ...Further, we've seen rashes of failures on > > the same aircraft over a spread of manufacturing date codes. > >I've had 3, possibly 4 switch failures in my RV-9A. Another RV-9A had 2 >similar failures. All except one were Carling switches Understand. >I am reasonably convinced that the combination of vibration, terminal rivet >construction and high current loading is causing these failures. I will >continue my experiment with a straight switch substitution to see if the >Micro Switch brand has higher vibration tolerance. I will report any >failures or successes in the next 100 hours of operation. I can guarantee that the MicroSwitch product is immune from this failure mode. >Even if the new switches are successful, after 100 hours I will secure the >wiring harness more positively to minimize vibration. The combination of >(potentially) better switches and proper wire grooming will hopefully give >me long term reliability. Bundle securement is not so important as UNCOUPLING of the bundle with respect to the tabs. Imagine a wire bundle that runs right behind the switches. Pigtails should not coming out of the bundle directly to the switch. Instead, use about 2" of wire that exits the bundle AWAY from the switch and then does a 180-degree turn to drop onto the fast-on tab. >I hope others have learned from the problems I've had and are looking at >their own installations for potential problems. Good Luck to everybody. I'm not sure we've confirmed anything yet. It's not an electrical ratings issue and unlikely to be a QA issue. This leaves us with mechanical issues that exceed design limits. The soft-coupling of bundle-to- tab by way of long service loops would absolutely break the offending force path. If you were to splice 2" pieces to your existing pigtails and allow them to make a lazy curl in the bundle to tab transition, I'll bet the Carlings would perform to expectations. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
From: "William Slaughter" <willslau(at)comcast.net>
Subject: Re: Toggle Switches with Fast-On Tabs
Date: Sep 25, 2008
Hi Bob, Can you furnish a list of the Microswitch part numbers to correlate to the various switch configurations as shown in Fig 11-14, particularly the progressive transfer switches? I have some of the Carlings on hand, but am considering switching to the more robust product line before installing anything. Thanks. William Slaughter RV-8 -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, September 25, 2008 5:13 PM Subject: RE: AeroElectric-List: Re: Toggle Switches with Fast-On Tabs > > >Hi Bob, see my commments: > > > ...Further, we've seen rashes of failures on > > the same aircraft over a spread of manufacturing date codes. > >I've had 3, possibly 4 switch failures in my RV-9A. Another RV-9A had 2 >similar failures. All except one were Carling switches Understand. >I am reasonably convinced that the combination of vibration, terminal rivet >construction and high current loading is causing these failures. I will >continue my experiment with a straight switch substitution to see if the >Micro Switch brand has higher vibration tolerance. I will report any >failures or successes in the next 100 hours of operation. I can guarantee that the MicroSwitch product is immune from this failure mode. >Even if the new switches are successful, after 100 hours I will secure the >wiring harness more positively to minimize vibration. The combination of >(potentially) better switches and proper wire grooming will hopefully give >me long term reliability. Bundle securement is not so important as UNCOUPLING of the bundle with respect to the tabs. Imagine a wire bundle that runs right behind the switches. Pigtails should not coming out of the bundle directly to the switch. Instead, use about 2" of wire that exits the bundle AWAY from the switch and then does a 180-degree turn to drop onto the fast-on tab. >I hope others have learned from the problems I've had and are looking at >their own installations for potential problems. Good Luck to everybody. I'm not sure we've confirmed anything yet. It's not an electrical ratings issue and unlikely to be a QA issue. This leaves us with mechanical issues that exceed design limits. The soft-coupling of bundle-to- tab by way of long service loops would absolutely break the offending force path. If you were to splice 2" pieces to your existing pigtails and allow them to make a lazy curl in the bundle to tab transition, I'll bet the Carlings would perform to expectations. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 26, 2008
From: Ed Holyoke <bicyclop(at)pacbell.net>
Subject: A Tale of Two Batteries
Howdy, I recently bought the West Mountain Radio CBA and did some tests on some old batteries. Here's what I found: Battery 1 came with our airplane and after about 2 years we decided to replace it. It is a Conorde RG-25XC rated at 25 ah. It was removed from the airplane in January of 06 and charged 2 or 3 times since. It mostly just sat. I charged it with a BatteryMINDer at 8 amps and discharged it at 4amps to 10.5v. It tested to 12.1 ah, or about half it's rated capacity. Battery 2 is the same make and model and is the battery which replaced Bat 1 in Jan/06. This battery gave no problems in service until the day that the positive cable chafed through and shorted against a stainless braided brake line in flight. It resulted in a smoke filled cabin and an emergency landing (on airport). When I arrived on the scene an hour and a half later, I moved the brake line away from the cable and measured 5 volts on the battery. Needless to say, the cable has been protected from this ever happening again. The battery was charged overnight (on an ancient non-smart charger) and returned to service. A month or two later, it failed to start the airplane and was changed out for another RG-25 XC. This was all about a year ago. I don't remember if I charged this battery after removal, but it was at 12.66 volts before I charged it for this test. I discharged it at 4 amps to 10.5v. It, surprisingly, came in at 25.4 ah - right at rated capacity. I'm going to swap it back into the airplane long enough to test Battery 3 and see how that one is doing. I also tested a friend's 35 ah Concorde battery which is a year old but hasn't yet seen service at 4 amps to 10.5v and got 37.4 ah out of it. In the meantime, my computer's UPS quit working so I pulled the 8 ah battery out of it and found it to be 5.3v. I extended the leads out of the UPS box and hooked them to Battery 1 and hooked my computer back up to it. The float voltage seems high at 13.72, but I'm not worried about it seeing as how that battery is useless for much else and if it fails at some point, I have another to replace it. Hope I didn't bore Y'all too much, Ed Holyoke ________________________________________________________________________________
From: "bob noffs" <icubob(at)newnorth.net>
Subject: dielectric grease
Date: Sep 27, 2008
bob, do you recommend using dielectric grease on any connections? where the copper terminates on steel? i thought i had been told to use it between an alum and copper joint. bob noffs ________________________________________________________________________________
Date: Sep 27, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: A Tale of Two Batteries
> >Howdy, > >I recently bought the West Mountain Radio CBA and did some tests on some >old batteries. Here's what I found: >Hope I didn't bore Y'all too much, > >Ed Holyoke Ed, thank you for sharing this with us. And congratulations on your decision to expand your toolbox for understanding. I've listened to and read a lot of conversation about battery condition and performance where the participants formulated hypotheses based on conjecture . . . and then acted on those hypotheses (or advised others to act on those hypotheses) in what was mostly a waste of $time$. Your willingness to replace conjecture with data and understanding will serve you well . . . your encouragement of others to do likewise will serve them well. As a side note, there are tests conducted on deliberately abused batteries to demonstrate an ability to recover from that abuse. I don't recall the specifics but they involved taking a battery down to 0 capacity for a long period of time and then cycling it through a series of charge and discharge protocols while measuring the useful capacity of the battery during each discharge. All of Concorde's products are qualified to these requirements as are Hawker's aircraft products. I've seen quantities of $high$ batteries sitting in Concorde's warranty return pile where the techs reported successful recovery of a substantial number of the returns. Some had be discharged and out of service for months. I don't recall the figures but somewhere around 1/3 were recoverable to 80% or better capacity. This data suggests that many batteries are returned for warranty not because they are defective. They came back because the user (or his mechanic) didn't understand how ingredients that go into the recipe for success in aircraft power generation and storage systems worked together. Batteries are secretive buggers. There are no dials, no diagnostic ports, and a host of vulnerabilities to optimized performance. Without tools of investigation and maintenance, the user is playing the odds that don't get any better by being ignorant. As you've discovered, it takes $time$ and $investment$ to achieve your level of understanding. Most airplane owners are not compelled to make such expenditures. That's why I've often recommend that folks buy the least expensive battery and replace it every year. This protocol may well provide a superior system reliability with a minimum cost of ownership. It's that CBA a slick tool? By the way, you can use it also as a data acquisition system. If you'd like to measure and plot a voltage over a long period of time, set it up to "test" a battery with 0.01A of discharge rate. If this level of load is so small that it doesn't adversely affect your system under investigation, then the software will dutifully march off and gather the data for you and put it out in nice plots. I own two of those critters. Bob . . . ________________________________________________________________________________
Date: Sep 27, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: dielectric grease
>bob, > do you recommend using dielectric grease on any connections? where the > copper terminates on steel? i thought i had been told to use it between > an alum and copper joint. > bob > noffs Generally we don't put copper and steel right together. Terminals are plated with tin to provide a material in the "sandwich" that goes toward minimizing the effects of electrolytic corrosion. Keep in mind that this corrosion needs oxygen and moisture to move forward. Getting the joint gas-tight goes a long way toward holding corrosion at bay. However, this does not preclude prophylactic measures like silicone grease on the before-mating parts, or encapsulation by painting on some manner of sealant on the finished joint. I can tell you that paints, gunks and goos are very process sensitive on the production line and we work really hard to avoid using them. If you've got the right materials coming together under the right forces in the first place, the "extra protection" is not needed. Now, when you're wiring up a boat or other machine exposed to a humid, salt-air environment, you can't do too much to forestall future maintenance. But outside this environmental extreme, there's probably not much value to be realized with added grease in the joints. I've never seen it done on a production airplane. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: Sep 27, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Toggle Switches with Fast-On Tabs
> > >Hi Bob, >Can you furnish a list of the Microswitch part numbers to correlate to the >various switch configurations as shown in Fig 11-14, particularly the >progressive transfer switches? I have some of the Carlings on hand, but am >considering switching to the more robust product line before installing >anything. Thanks. > >William Slaughter >RV-8 There's a Microswitch catalog for the TL series devices on my server at: http://aeroelectric.com/Mfgr_Data/Switches/Microswitch_TL-Series.pdf There is a correlation between the dash-numbers I adopted (and B&C retained) for identifying switch functionality. An S700-1-3 is a Micoroswitch 1TL1-3 An S700-2-10 is a Microswitch 2TL1-10 etc. Bob . . . ________________________________________________________________________________
From: Jim Corner <jcorner(at)shaw.ca>
Subject: Dynon EMS D-10 and P-Mags
Date: Sep 27, 2008
I have the above combination on my 0-235 Lycoming powered Kitfox and all D-10 functions work great except the tachometer function fails above 1500 RPM. I have been following up with both Dynon and E-MAG ignitions, but I have yet to solve the problem. Has anyone had any experience with this combination that can shed some light on my problem? I have the latest firmware from E-Mag on their series 114 ignitions, Jim ________________________________________________________________________________
From: "Steve McCartney" <rv3.flyr(at)yahoo.com>
Subject:
Date: Sep 27, 2008
I'm not finding much info about the use of unshielded twisted pair wiring. When should this technique be used, and when is it unnecessary? ----------- Steve McC rv3.flyr(at)yahoo.com 805.479.2260 ________________________________________________________________________________
Date: Sep 28, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re:
>I'm not finding much info about the use of unshielded twisted pair >wiring. When should this technique be used, and when is it unnecessary? Only when it is called out on the installation drawings for some piece of equipment. We NEVER twist a combination of wires in a production airplane to meet a design goal. When the circuit being wired is deemed a potential antagonist or victim then the installation instructions will speak to a recommended use of shielded wire. The short answer is that it is rarely necessary. Bob . . . ________________________________________________________________________________
Date: Sep 28, 2008
From: Ed Holyoke <bicyclop(at)pacbell.net>
Subject: Re: A Tale of Two Batteries
Howdy Bob, I'd be interested to find out what the protocols are for salvaging damaged batteries. Got nothing to lose, after all. I guess I'll poke around the Concorde site and see if I can dig anything up. I was going to build the test rig you wrote about long ago with the electric clock and the zener diode cutout circuit, but I never go around to it and, when I read about the CBA, I thought "That's what I really want". It is a much more sophisticated and capable tool. On another note, is the VDC battery minder - aviation adjusted that much better than the standard 12248 charger which can be had about $65 cheaper? What is the AA, just a tenth of an amp or so lower setting, or is it magic? Pax, Ed Holyoke > > As a side note, there are tests conducted on deliberately > abused batteries to demonstrate an ability to recover from > that abuse. I don't recall the specifics but they involved > taking a battery down to 0 capacity for a long period of > time and then cycling it through a series of charge and > discharge protocols while measuring the useful capacity > of the battery during each discharge. All of Concorde's > products are qualified to these requirements as are > Hawker's aircraft products. > > I've seen quantities of $high$ batteries sitting in Concorde's > warranty return pile where the techs reported successful > recovery of a substantial number of the returns. Some had > be discharged and out of service for months. I don't > recall the figures but somewhere around 1/3 were > recoverable to 80% or better capacity. > > This data suggests that many batteries are returned > for warranty not because they are defective. They > came back because the user (or his mechanic) didn't understand > how ingredients that go into the recipe for success > in aircraft power generation and storage systems > worked together. > > Batteries are secretive buggers. There are no dials, > no diagnostic ports, and a host of vulnerabilities > to optimized performance. Without tools of investigation > and maintenance, the user is playing the odds that > don't get any better by being ignorant. > > As you've discovered, it takes $time$ and $investment$ > to achieve your level of understanding. Most airplane > owners are not compelled to make such expenditures. That's > why I've often recommend that folks buy the least > expensive battery and replace it every year. This > protocol may well provide a superior system reliability > with a minimum cost of ownership. > > It's that CBA a slick tool? By the way, you can use > it also as a data acquisition system. If you'd like to > measure and plot a voltage over a long period of time, > set it up to "test" a battery with 0.01A of discharge > rate. If this level of load is so small that it doesn't > adversely affect your system under investigation, then > the software will dutifully march off and gather the > data for you and put it out in nice plots. I own > two of those critters. > > Bob . . . > > ________________________________________________________________________________
Date: Sep 28, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: A Tale of Two Batteries
> >Howdy Bob, > >I'd be interested to find out what the protocols are for salvaging damaged >batteries. Got nothing to lose, after all. I guess I'll poke around the >Concorde site and see if I can dig anything up. I may have the process document someplace. If I can't find it, I can get it from Concorde. It's not "magic". It doesn't use any form of incantation like de-sulfation pulsers, etc. As I recall it starts with a controlled over-charge that pushes the terminal voltage pretty high until internal resistance to come down. I think I recall Skip talking about 20 volts or more on a 12v battery. After the battery demonstrates a willingness to draw current in a more typical recharge mode, the battery is subjected to a series of constant current, charge- discharge cycles with each discharge cycle being quantified for energy delivered. Early in the process, successive discharges grow stronger. After the ability to store energy flattens out, the battery may be either deemed serviceable or ready for re-cycling. This process won't "refurbish" a worn out battery but it may "wake up" a mis-treated battery. >I was going to build the test rig you wrote about long ago with the >electric clock and the zener diode cutout circuit, but I never go around >to it and, when I read about the CBA, I thought "That's what I really >want". It is a much more sophisticated and capable tool. Yup, in this business tools is what it's all about. No matter how much you understand, you're not going to drive that nail without at least a hammer. Without the hammer, you're skill-set remains un-quantified and un-demonstrated. >On another note, is the VDC battery minder - aviation adjusted that much >better than the standard 12248 charger which can be had about $65 cheaper? ALL of the smart chargers that do constant current, voltage limited charging, top-off followed by a maintenance mode are about 1000 light years ahead of any "trickle- charger" of yesteryear. Like this: http://www.aeroelectric.com/Pictures/Curves/Ideal_Recharge_Protocol.jpg Now, here's the measured performance on a variety of "smart chargers" . . . http://www.aeroelectric.com/Pictures/Curves/Battery_Minder_Recharge.pdf http://www.aeroelectric.com/Pictures/Curves/Battery_Tender_Recharge.pdf http://aeroelectric.com/Pictures/Battery_Chargers/Schumacher_Chargers/SC2500-50AH.jpg http://www.aeroelectric.com/Pictures/Curves/HF93258_1.jpg http://www.aeroelectric.com/Pictures/Curves/schumacher_2.jpg http://www.aeroelectric.com/Pictures/Curves/schumacher_3.jpg http://www.aeroelectric.com/Pictures/Curves/schumacher_5.jpg None of these charge/maintenance protocols are identical to another one. Some don't exactly capture the "Idealized Protocol". Nonetheless, every guy behind the counter in a booth at OSH will point to HIS recharge curve and compare it with the recharge curve for the charger being sold across the isle and do his best to convince you that HIS is better. This is sort of like water districts of various cities extolling the virtues of THEIR water treatment by taking swipes at each other. They ignore the fact that only in the last 100 years or so of mankind's existence on the planet has the threat of water-borne disease become non-existent because of our understanding of simple-ideas that have nothing to do with hardness, taste, or perhaps even clarity of the product. And so it is with battery chargers. They're all so good compared to what we had 20 years ago that the only thing they can do is snipe at each other! > What is the AA, just a tenth of an amp or so lower setting, or is it magic? Not sure about what you're asking. Are you wondering what test currents are appropriate for testing AA cells? Depends on the technology. We know that the higher the load, the lower the apparent capacity due to internal losses in the cell. The discharge current selected for testing purposes has to do with the application in which you choose to use the product. For example, a wrist watch runs on fractions of microamps so you can get most of the energy out of that itty-bitty button cell in spite of it's 'horrendous' internal impedance. On the other hand, my digital camera with the big LCD color screen needs 500 mA or more of supply current. In this case, performance is optimized by selecting cells with the lowest practical resistance which is not necessarily the cell with the greatest capacity. I did all the tests on alkaline cells with 5 ohm load


September 12, 2008 - September 28, 2008

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